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linuxdebug/tools/testing/selftests/seccomp/seccomp_bpf.c

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null pointer error
2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
*
* Test code for seccomp bpf.
*/
#define _GNU_SOURCE
#include <sys/types.h>
/*
* glibc 2.26 and later have SIGSYS in siginfo_t. Before that,
* we need to use the kernel's siginfo.h file and trick glibc
* into accepting it.
*/
#if !__GLIBC_PREREQ(2, 26)
# include <asm/siginfo.h>
# define __have_siginfo_t 1
# define __have_sigval_t 1
# define __have_sigevent_t 1
#endif
#include <errno.h>
#include <linux/filter.h>
#include <sys/prctl.h>
#include <sys/ptrace.h>
#include <sys/user.h>
#include <linux/prctl.h>
#include <linux/ptrace.h>
#include <linux/seccomp.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <stddef.h>
#include <stdbool.h>
#include <string.h>
#include <time.h>
#include <limits.h>
#include <linux/elf.h>
#include <sys/uio.h>
#include <sys/utsname.h>
#include <sys/fcntl.h>
#include <sys/mman.h>
#include <sys/times.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/kcmp.h>
#include <sys/resource.h>
#include <sys/capability.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <poll.h>
#include "../kselftest_harness.h"
#include "../clone3/clone3_selftests.h"
/* Attempt to de-conflict with the selftests tree. */
#ifndef SKIP
#define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__)
#endif
#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
#ifndef PR_SET_PTRACER
# define PR_SET_PTRACER 0x59616d61
#endif
#ifndef PR_SET_NO_NEW_PRIVS
#define PR_SET_NO_NEW_PRIVS 38
#define PR_GET_NO_NEW_PRIVS 39
#endif
#ifndef PR_SECCOMP_EXT
#define PR_SECCOMP_EXT 43
#endif
#ifndef SECCOMP_EXT_ACT
#define SECCOMP_EXT_ACT 1
#endif
#ifndef SECCOMP_EXT_ACT_TSYNC
#define SECCOMP_EXT_ACT_TSYNC 1
#endif
#ifndef SECCOMP_MODE_STRICT
#define SECCOMP_MODE_STRICT 1
#endif
#ifndef SECCOMP_MODE_FILTER
#define SECCOMP_MODE_FILTER 2
#endif
#ifndef SECCOMP_RET_ALLOW
struct seccomp_data {
int nr;
__u32 arch;
__u64 instruction_pointer;
__u64 args[6];
};
#endif
#ifndef SECCOMP_RET_KILL_PROCESS
#define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
#define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
#endif
#ifndef SECCOMP_RET_KILL
#define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
#define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
#define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
#define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
#define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
#endif
#ifndef SECCOMP_RET_LOG
#define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
#endif
#ifndef __NR_seccomp
# if defined(__i386__)
# define __NR_seccomp 354
# elif defined(__x86_64__)
# define __NR_seccomp 317
# elif defined(__arm__)
# define __NR_seccomp 383
# elif defined(__aarch64__)
# define __NR_seccomp 277
# elif defined(__riscv)
# define __NR_seccomp 277
# elif defined(__csky__)
# define __NR_seccomp 277
# elif defined(__hppa__)
# define __NR_seccomp 338
# elif defined(__powerpc__)
# define __NR_seccomp 358
# elif defined(__s390__)
# define __NR_seccomp 348
# elif defined(__xtensa__)
# define __NR_seccomp 337
# elif defined(__sh__)
# define __NR_seccomp 372
# else
# warning "seccomp syscall number unknown for this architecture"
# define __NR_seccomp 0xffff
# endif
#endif
#ifndef SECCOMP_SET_MODE_STRICT
#define SECCOMP_SET_MODE_STRICT 0
#endif
#ifndef SECCOMP_SET_MODE_FILTER
#define SECCOMP_SET_MODE_FILTER 1
#endif
#ifndef SECCOMP_GET_ACTION_AVAIL
#define SECCOMP_GET_ACTION_AVAIL 2
#endif
#ifndef SECCOMP_GET_NOTIF_SIZES
#define SECCOMP_GET_NOTIF_SIZES 3
#endif
#ifndef SECCOMP_FILTER_FLAG_TSYNC
#define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
#endif
#ifndef SECCOMP_FILTER_FLAG_LOG
#define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
#endif
#ifndef SECCOMP_FILTER_FLAG_SPEC_ALLOW
#define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
#endif
#ifndef PTRACE_SECCOMP_GET_METADATA
#define PTRACE_SECCOMP_GET_METADATA 0x420d
struct seccomp_metadata {
__u64 filter_off; /* Input: which filter */
__u64 flags; /* Output: filter's flags */
};
#endif
#ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER
#define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
#endif
#ifndef SECCOMP_RET_USER_NOTIF
#define SECCOMP_RET_USER_NOTIF 0x7fc00000U
#define SECCOMP_IOC_MAGIC '!'
#define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
#define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
#define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
#define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
/* Flags for seccomp notification fd ioctl. */
#define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
#define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
struct seccomp_notif_resp)
#define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64)
struct seccomp_notif {
__u64 id;
__u32 pid;
__u32 flags;
struct seccomp_data data;
};
struct seccomp_notif_resp {
__u64 id;
__s64 val;
__s32 error;
__u32 flags;
};
struct seccomp_notif_sizes {
__u16 seccomp_notif;
__u16 seccomp_notif_resp;
__u16 seccomp_data;
};
#endif
#ifndef SECCOMP_IOCTL_NOTIF_ADDFD
/* On success, the return value is the remote process's added fd number */
#define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \
struct seccomp_notif_addfd)
/* valid flags for seccomp_notif_addfd */
#define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */
struct seccomp_notif_addfd {
__u64 id;
__u32 flags;
__u32 srcfd;
__u32 newfd;
__u32 newfd_flags;
};
#endif
#ifndef SECCOMP_ADDFD_FLAG_SEND
#define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */
#endif
struct seccomp_notif_addfd_small {
__u64 id;
char weird[4];
};
#define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \
SECCOMP_IOW(3, struct seccomp_notif_addfd_small)
struct seccomp_notif_addfd_big {
union {
struct seccomp_notif_addfd addfd;
char buf[sizeof(struct seccomp_notif_addfd) + 8];
};
};
#define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \
SECCOMP_IOWR(3, struct seccomp_notif_addfd_big)
#ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY
#define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
#define PTRACE_EVENTMSG_SYSCALL_EXIT 2
#endif
#ifndef SECCOMP_USER_NOTIF_FLAG_CONTINUE
#define SECCOMP_USER_NOTIF_FLAG_CONTINUE 0x00000001
#endif
#ifndef SECCOMP_FILTER_FLAG_TSYNC_ESRCH
#define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)
#endif
#ifndef SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV
#define SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV (1UL << 5)
#endif
#ifndef seccomp
int seccomp(unsigned int op, unsigned int flags, void *args)
{
errno = 0;
return syscall(__NR_seccomp, op, flags, args);
}
#endif
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]))
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n]) + sizeof(__u32))
#else
#error "wut? Unknown __BYTE_ORDER__?!"
#endif
#define SIBLING_EXIT_UNKILLED 0xbadbeef
#define SIBLING_EXIT_FAILURE 0xbadface
#define SIBLING_EXIT_NEWPRIVS 0xbadfeed
static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2)
{
#ifdef __NR_kcmp
errno = 0;
return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2);
#else
errno = ENOSYS;
return -1;
#endif
}
/* Have TH_LOG report actual location filecmp() is used. */
#define filecmp(pid1, pid2, fd1, fd2) ({ \
int _ret; \
\
_ret = __filecmp(pid1, pid2, fd1, fd2); \
if (_ret != 0) { \
if (_ret < 0 && errno == ENOSYS) { \
TH_LOG("kcmp() syscall missing (test is less accurate)");\
_ret = 0; \
} \
} \
_ret; })
TEST(kcmp)
{
int ret;
ret = __filecmp(getpid(), getpid(), 1, 1);
EXPECT_EQ(ret, 0);
if (ret != 0 && errno == ENOSYS)
SKIP(return, "Kernel does not support kcmp() (missing CONFIG_KCMP?)");
}
TEST(mode_strict_support)
{
long ret;
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support CONFIG_SECCOMP");
}
syscall(__NR_exit, 0);
}
TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
{
long ret;
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support CONFIG_SECCOMP");
}
syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
NULL, NULL, NULL);
EXPECT_FALSE(true) {
TH_LOG("Unreachable!");
}
}
/* Note! This doesn't test no new privs behavior */
TEST(no_new_privs_support)
{
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
EXPECT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
}
/* Tests kernel support by checking for a copy_from_user() fault on NULL. */
TEST(mode_filter_support)
{
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EFAULT, errno) {
TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!");
}
}
TEST(mode_filter_without_nnp)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0);
ASSERT_LE(0, ret) {
TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS");
}
errno = 0;
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
/* Succeeds with CAP_SYS_ADMIN, fails without */
/* TODO(wad) check caps not euid */
if (geteuid()) {
EXPECT_EQ(-1, ret);
EXPECT_EQ(EACCES, errno);
} else {
EXPECT_EQ(0, ret);
}
}
#define MAX_INSNS_PER_PATH 32768
TEST(filter_size_limits)
{
int i;
int count = BPF_MAXINSNS + 1;
struct sock_filter allow[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_filter *filter;
struct sock_fprog prog = { };
long ret;
filter = calloc(count, sizeof(*filter));
ASSERT_NE(NULL, filter);
for (i = 0; i < count; i++)
filter[i] = allow[0];
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
prog.filter = filter;
prog.len = count;
/* Too many filter instructions in a single filter. */
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_NE(0, ret) {
TH_LOG("Installing %d insn filter was allowed", prog.len);
}
/* One less is okay, though. */
prog.len -= 1;
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Installing %d insn filter wasn't allowed", prog.len);
}
}
TEST(filter_chain_limits)
{
int i;
int count = BPF_MAXINSNS;
struct sock_filter allow[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_filter *filter;
struct sock_fprog prog = { };
long ret;
filter = calloc(count, sizeof(*filter));
ASSERT_NE(NULL, filter);
for (i = 0; i < count; i++)
filter[i] = allow[0];
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
prog.filter = filter;
prog.len = 1;
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_EQ(0, ret);
prog.len = count;
/* Too many total filter instructions. */
for (i = 0; i < MAX_INSNS_PER_PATH; i++) {
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
if (ret != 0)
break;
}
ASSERT_NE(0, ret) {
TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)",
i, count, i * (count + 4));
}
}
TEST(mode_filter_cannot_move_to_strict)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EINVAL, errno);
}
TEST(mode_filter_get_seccomp)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
EXPECT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
EXPECT_EQ(2, ret);
}
TEST(ALLOW_all)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
ASSERT_EQ(0, ret);
}
TEST(empty_prog)
{
struct sock_filter filter[] = {
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EINVAL, errno);
}
TEST(log_all)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
pid_t parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
ASSERT_EQ(0, ret);
/* getppid() should succeed and be logged (no check for logging) */
EXPECT_EQ(parent, syscall(__NR_getppid));
}
TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, 0x10000000U),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
ASSERT_EQ(0, ret);
EXPECT_EQ(0, syscall(__NR_getpid)) {
TH_LOG("getpid() shouldn't ever return");
}
}
/* return code >= 0x80000000 is unused. */
TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, 0x90000000U),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
ASSERT_EQ(0, ret);
EXPECT_EQ(0, syscall(__NR_getpid)) {
TH_LOG("getpid() shouldn't ever return");
}
}
TEST_SIGNAL(KILL_all, SIGSYS)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
ASSERT_EQ(0, ret);
}
TEST_SIGNAL(KILL_one, SIGSYS)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
pid_t parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
ASSERT_EQ(0, ret);
EXPECT_EQ(parent, syscall(__NR_getppid));
/* getpid() should never return. */
EXPECT_EQ(0, syscall(__NR_getpid));
}
TEST_SIGNAL(KILL_one_arg_one, SIGSYS)
{
void *fatal_address;
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_times, 1, 0),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
/* Only both with lower 32-bit for now. */
BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K,
(unsigned long)&fatal_address, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
pid_t parent = getppid();
struct tms timebuf;
clock_t clock = times(&timebuf);
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
ASSERT_EQ(0, ret);
EXPECT_EQ(parent, syscall(__NR_getppid));
EXPECT_LE(clock, syscall(__NR_times, &timebuf));
/* times() should never return. */
EXPECT_EQ(0, syscall(__NR_times, &fatal_address));
}
TEST_SIGNAL(KILL_one_arg_six, SIGSYS)
{
#ifndef __NR_mmap2
int sysno = __NR_mmap;
#else
int sysno = __NR_mmap2;
#endif
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, sysno, 1, 0),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
/* Only both with lower 32-bit for now. */
BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
pid_t parent = getppid();
int fd;
void *map1, *map2;
int page_size = sysconf(_SC_PAGESIZE);
ASSERT_LT(0, page_size);
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
ASSERT_EQ(0, ret);
fd = open("/dev/zero", O_RDONLY);
ASSERT_NE(-1, fd);
EXPECT_EQ(parent, syscall(__NR_getppid));
map1 = (void *)syscall(sysno,
NULL, page_size, PROT_READ, MAP_PRIVATE, fd, page_size);
EXPECT_NE(MAP_FAILED, map1);
/* mmap2() should never return. */
map2 = (void *)syscall(sysno,
NULL, page_size, PROT_READ, MAP_PRIVATE, fd, 0x0C0FFEE);
EXPECT_EQ(MAP_FAILED, map2);
/* The test failed, so clean up the resources. */
munmap(map1, page_size);
munmap(map2, page_size);
close(fd);
}
/* This is a thread task to die via seccomp filter violation. */
void *kill_thread(void *data)
{
bool die = (bool)data;
if (die) {
prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
return (void *)SIBLING_EXIT_FAILURE;
}
return (void *)SIBLING_EXIT_UNKILLED;
}
enum kill_t {
KILL_THREAD,
KILL_PROCESS,
RET_UNKNOWN
};
/* Prepare a thread that will kill itself or both of us. */
void kill_thread_or_group(struct __test_metadata *_metadata,
enum kill_t kill_how)
{
pthread_t thread;
void *status;
/* Kill only when calling __NR_prctl. */
struct sock_filter filter_thread[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog_thread = {
.len = (unsigned short)ARRAY_SIZE(filter_thread),
.filter = filter_thread,
};
int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAA;
struct sock_filter filter_process[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
BPF_STMT(BPF_RET|BPF_K, kill),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog_process = {
.len = (unsigned short)ARRAY_SIZE(filter_process),
.filter = filter_process,
};
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
kill_how == KILL_THREAD ? &prog_thread
: &prog_process));
/*
* Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
* flag cannot be downgraded by a new filter.
*/
if (kill_how == KILL_PROCESS)
ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
/* Start a thread that will exit immediately. */
ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
ASSERT_EQ(0, pthread_join(thread, &status));
ASSERT_EQ(SIBLING_EXIT_UNKILLED, (unsigned long)status);
/* Start a thread that will die immediately. */
ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)true));
ASSERT_EQ(0, pthread_join(thread, &status));
ASSERT_NE(SIBLING_EXIT_FAILURE, (unsigned long)status);
/*
* If we get here, only the spawned thread died. Let the parent know
* the whole process didn't die (i.e. this thread, the spawner,
* stayed running).
*/
exit(42);
}
TEST(KILL_thread)
{
int status;
pid_t child_pid;
child_pid = fork();
ASSERT_LE(0, child_pid);
if (child_pid == 0) {
kill_thread_or_group(_metadata, KILL_THREAD);
_exit(38);
}
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
/* If only the thread was killed, we'll see exit 42. */
ASSERT_TRUE(WIFEXITED(status));
ASSERT_EQ(42, WEXITSTATUS(status));
}
TEST(KILL_process)
{
int status;
pid_t child_pid;
child_pid = fork();
ASSERT_LE(0, child_pid);
if (child_pid == 0) {
kill_thread_or_group(_metadata, KILL_PROCESS);
_exit(38);
}
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
/* If the entire process was killed, we'll see SIGSYS. */
ASSERT_TRUE(WIFSIGNALED(status));
ASSERT_EQ(SIGSYS, WTERMSIG(status));
}
TEST(KILL_unknown)
{
int status;
pid_t child_pid;
child_pid = fork();
ASSERT_LE(0, child_pid);
if (child_pid == 0) {
kill_thread_or_group(_metadata, RET_UNKNOWN);
_exit(38);
}
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
/* If the entire process was killed, we'll see SIGSYS. */
EXPECT_TRUE(WIFSIGNALED(status)) {
TH_LOG("Unknown SECCOMP_RET is only killing the thread?");
}
ASSERT_EQ(SIGSYS, WTERMSIG(status));
}
/* TODO(wad) add 64-bit versus 32-bit arg tests. */
TEST(arg_out_of_range)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EINVAL, errno);
}
#define ERRNO_FILTER(name, errno) \
struct sock_filter _read_filter_##name[] = { \
BPF_STMT(BPF_LD|BPF_W|BPF_ABS, \
offsetof(struct seccomp_data, nr)), \
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), \
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | errno), \
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), \
}; \
struct sock_fprog prog_##name = { \
.len = (unsigned short)ARRAY_SIZE(_read_filter_##name), \
.filter = _read_filter_##name, \
}
/* Make sure basic errno values are correctly passed through a filter. */
TEST(ERRNO_valid)
{
ERRNO_FILTER(valid, E2BIG);
long ret;
pid_t parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_valid);
ASSERT_EQ(0, ret);
EXPECT_EQ(parent, syscall(__NR_getppid));
EXPECT_EQ(-1, read(-1, NULL, 0));
EXPECT_EQ(E2BIG, errno);
}
/* Make sure an errno of zero is correctly handled by the arch code. */
TEST(ERRNO_zero)
{
ERRNO_FILTER(zero, 0);
long ret;
pid_t parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_zero);
ASSERT_EQ(0, ret);
EXPECT_EQ(parent, syscall(__NR_getppid));
/* "errno" of 0 is ok. */
EXPECT_EQ(0, read(-1, NULL, 0));
}
/*
* The SECCOMP_RET_DATA mask is 16 bits wide, but errno is smaller.
* This tests that the errno value gets capped correctly, fixed by
* 580c57f10768 ("seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO").
*/
TEST(ERRNO_capped)
{
ERRNO_FILTER(capped, 4096);
long ret;
pid_t parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_capped);
ASSERT_EQ(0, ret);
EXPECT_EQ(parent, syscall(__NR_getppid));
EXPECT_EQ(-1, read(-1, NULL, 0));
EXPECT_EQ(4095, errno);
}
/*
* Filters are processed in reverse order: last applied is executed first.
* Since only the SECCOMP_RET_ACTION mask is tested for return values, the
* SECCOMP_RET_DATA mask results will follow the most recently applied
* matching filter return (and not the lowest or highest value).
*/
TEST(ERRNO_order)
{
ERRNO_FILTER(first, 11);
ERRNO_FILTER(second, 13);
ERRNO_FILTER(third, 12);
long ret;
pid_t parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_first);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_second);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_third);
ASSERT_EQ(0, ret);
EXPECT_EQ(parent, syscall(__NR_getppid));
EXPECT_EQ(-1, read(-1, NULL, 0));
EXPECT_EQ(12, errno);
}
FIXTURE(TRAP) {
struct sock_fprog prog;
};
FIXTURE_SETUP(TRAP)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
memset(&self->prog, 0, sizeof(self->prog));
self->prog.filter = malloc(sizeof(filter));
ASSERT_NE(NULL, self->prog.filter);
memcpy(self->prog.filter, filter, sizeof(filter));
self->prog.len = (unsigned short)ARRAY_SIZE(filter);
}
FIXTURE_TEARDOWN(TRAP)
{
if (self->prog.filter)
free(self->prog.filter);
}
TEST_F_SIGNAL(TRAP, dfl, SIGSYS)
{
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
ASSERT_EQ(0, ret);
syscall(__NR_getpid);
}
/* Ensure that SIGSYS overrides SIG_IGN */
TEST_F_SIGNAL(TRAP, ign, SIGSYS)
{
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
signal(SIGSYS, SIG_IGN);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
ASSERT_EQ(0, ret);
syscall(__NR_getpid);
}
static siginfo_t TRAP_info;
static volatile int TRAP_nr;
static void TRAP_action(int nr, siginfo_t *info, void *void_context)
{
memcpy(&TRAP_info, info, sizeof(TRAP_info));
TRAP_nr = nr;
}
TEST_F(TRAP, handler)
{
int ret, test;
struct sigaction act;
sigset_t mask;
memset(&act, 0, sizeof(act));
sigemptyset(&mask);
sigaddset(&mask, SIGSYS);
act.sa_sigaction = &TRAP_action;
act.sa_flags = SA_SIGINFO;
ret = sigaction(SIGSYS, &act, NULL);
ASSERT_EQ(0, ret) {
TH_LOG("sigaction failed");
}
ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
ASSERT_EQ(0, ret) {
TH_LOG("sigprocmask failed");
}
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog);
ASSERT_EQ(0, ret);
TRAP_nr = 0;
memset(&TRAP_info, 0, sizeof(TRAP_info));
/* Expect the registers to be rolled back. (nr = error) may vary
* based on arch. */
ret = syscall(__NR_getpid);
/* Silence gcc warning about volatile. */
test = TRAP_nr;
EXPECT_EQ(SIGSYS, test);
struct local_sigsys {
void *_call_addr; /* calling user insn */
int _syscall; /* triggering system call number */
unsigned int _arch; /* AUDIT_ARCH_* of syscall */
} *sigsys = (struct local_sigsys *)
#ifdef si_syscall
&(TRAP_info.si_call_addr);
#else
&TRAP_info.si_pid;
#endif
EXPECT_EQ(__NR_getpid, sigsys->_syscall);
/* Make sure arch is non-zero. */
EXPECT_NE(0, sigsys->_arch);
EXPECT_NE(0, (unsigned long)sigsys->_call_addr);
}
FIXTURE(precedence) {
struct sock_fprog allow;
struct sock_fprog log;
struct sock_fprog trace;
struct sock_fprog error;
struct sock_fprog trap;
struct sock_fprog kill;
};
FIXTURE_SETUP(precedence)
{
struct sock_filter allow_insns[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_filter log_insns[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_LOG),
};
struct sock_filter trace_insns[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE),
};
struct sock_filter error_insns[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO),
};
struct sock_filter trap_insns[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP),
};
struct sock_filter kill_insns[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
};
memset(self, 0, sizeof(*self));
#define FILTER_ALLOC(_x) \
self->_x.filter = malloc(sizeof(_x##_insns)); \
ASSERT_NE(NULL, self->_x.filter); \
memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \
self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns)
FILTER_ALLOC(allow);
FILTER_ALLOC(log);
FILTER_ALLOC(trace);
FILTER_ALLOC(error);
FILTER_ALLOC(trap);
FILTER_ALLOC(kill);
}
FIXTURE_TEARDOWN(precedence)
{
#define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter)
FILTER_FREE(allow);
FILTER_FREE(log);
FILTER_FREE(trace);
FILTER_FREE(error);
FILTER_FREE(trap);
FILTER_FREE(kill);
}
TEST_F(precedence, allow_ok)
{
pid_t parent, res = 0;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
ASSERT_EQ(0, ret);
/* Should work just fine. */
res = syscall(__NR_getppid);
EXPECT_EQ(parent, res);
}
TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS)
{
pid_t parent, res = 0;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
ASSERT_EQ(0, ret);
/* Should work just fine. */
res = syscall(__NR_getppid);
EXPECT_EQ(parent, res);
/* getpid() should never return. */
res = syscall(__NR_getpid);
EXPECT_EQ(0, res);
}
TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS)
{
pid_t parent;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
/* getpid() should never return. */
EXPECT_EQ(0, syscall(__NR_getpid));
}
TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS)
{
pid_t parent;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
/* getpid() should never return. */
EXPECT_EQ(0, syscall(__NR_getpid));
}
TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS)
{
pid_t parent;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
/* getpid() should never return. */
EXPECT_EQ(0, syscall(__NR_getpid));
}
TEST_F(precedence, errno_is_third)
{
pid_t parent;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
EXPECT_EQ(0, syscall(__NR_getpid));
}
TEST_F(precedence, errno_is_third_in_any_order)
{
pid_t parent;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
EXPECT_EQ(0, syscall(__NR_getpid));
}
TEST_F(precedence, trace_is_fourth)
{
pid_t parent;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
/* No ptracer */
EXPECT_EQ(-1, syscall(__NR_getpid));
}
TEST_F(precedence, trace_is_fourth_in_any_order)
{
pid_t parent;
long ret;
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
/* No ptracer */
EXPECT_EQ(-1, syscall(__NR_getpid));
}
TEST_F(precedence, log_is_fifth)
{
pid_t mypid, parent;
long ret;
mypid = getpid();
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
/* Should also work just fine */
EXPECT_EQ(mypid, syscall(__NR_getpid));
}
TEST_F(precedence, log_is_fifth_in_any_order)
{
pid_t mypid, parent;
long ret;
mypid = getpid();
parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->log);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow);
ASSERT_EQ(0, ret);
/* Should work just fine. */
EXPECT_EQ(parent, syscall(__NR_getppid));
/* Should also work just fine */
EXPECT_EQ(mypid, syscall(__NR_getpid));
}
#ifndef PTRACE_O_TRACESECCOMP
#define PTRACE_O_TRACESECCOMP 0x00000080
#endif
/* Catch the Ubuntu 12.04 value error. */
#if PTRACE_EVENT_SECCOMP != 7
#undef PTRACE_EVENT_SECCOMP
#endif
#ifndef PTRACE_EVENT_SECCOMP
#define PTRACE_EVENT_SECCOMP 7
#endif
#define PTRACE_EVENT_MASK(status) ((status) >> 16)
bool tracer_running;
void tracer_stop(int sig)
{
tracer_running = false;
}
typedef void tracer_func_t(struct __test_metadata *_metadata,
pid_t tracee, int status, void *args);
void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee,
tracer_func_t tracer_func, void *args, bool ptrace_syscall)
{
int ret = -1;
struct sigaction action = {
.sa_handler = tracer_stop,
};
/* Allow external shutdown. */
tracer_running = true;
ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL));
errno = 0;
while (ret == -1 && errno != EINVAL)
ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0);
ASSERT_EQ(0, ret) {
kill(tracee, SIGKILL);
}
/* Wait for attach stop */
wait(NULL);
ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, ptrace_syscall ?
PTRACE_O_TRACESYSGOOD :
PTRACE_O_TRACESECCOMP);
ASSERT_EQ(0, ret) {
TH_LOG("Failed to set PTRACE_O_TRACESECCOMP");
kill(tracee, SIGKILL);
}
ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
tracee, NULL, 0);
ASSERT_EQ(0, ret);
/* Unblock the tracee */
ASSERT_EQ(1, write(fd, "A", 1));
ASSERT_EQ(0, close(fd));
/* Run until we're shut down. Must assert to stop execution. */
while (tracer_running) {
int status;
if (wait(&status) != tracee)
continue;
if (WIFSIGNALED(status)) {
/* Child caught a fatal signal. */
return;
}
if (WIFEXITED(status)) {
/* Child exited with code. */
return;
}
/* Check if we got an expected event. */
ASSERT_EQ(WIFCONTINUED(status), false);
ASSERT_EQ(WIFSTOPPED(status), true);
ASSERT_EQ(WSTOPSIG(status) & SIGTRAP, SIGTRAP) {
TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status));
}
tracer_func(_metadata, tracee, status, args);
ret = ptrace(ptrace_syscall ? PTRACE_SYSCALL : PTRACE_CONT,
tracee, NULL, 0);
ASSERT_EQ(0, ret);
}
/* Directly report the status of our test harness results. */
syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
}
/* Common tracer setup/teardown functions. */
void cont_handler(int num)
{ }
pid_t setup_trace_fixture(struct __test_metadata *_metadata,
tracer_func_t func, void *args, bool ptrace_syscall)
{
char sync;
int pipefd[2];
pid_t tracer_pid;
pid_t tracee = getpid();
/* Setup a pipe for clean synchronization. */
ASSERT_EQ(0, pipe(pipefd));
/* Fork a child which we'll promote to tracer */
tracer_pid = fork();
ASSERT_LE(0, tracer_pid);
signal(SIGALRM, cont_handler);
if (tracer_pid == 0) {
close(pipefd[0]);
start_tracer(_metadata, pipefd[1], tracee, func, args,
ptrace_syscall);
syscall(__NR_exit, 0);
}
close(pipefd[1]);
prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0);
read(pipefd[0], &sync, 1);
close(pipefd[0]);
return tracer_pid;
}
void teardown_trace_fixture(struct __test_metadata *_metadata,
pid_t tracer)
{
if (tracer) {
int status;
/*
* Extract the exit code from the other process and
* adopt it for ourselves in case its asserts failed.
*/
ASSERT_EQ(0, kill(tracer, SIGUSR1));
ASSERT_EQ(tracer, waitpid(tracer, &status, 0));
if (WEXITSTATUS(status))
_metadata->passed = 0;
}
}
/* "poke" tracer arguments and function. */
struct tracer_args_poke_t {
unsigned long poke_addr;
};
void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status,
void *args)
{
int ret;
unsigned long msg;
struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args;
ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
EXPECT_EQ(0, ret);
/* If this fails, don't try to recover. */
ASSERT_EQ(0x1001, msg) {
kill(tracee, SIGKILL);
}
/*
* Poke in the message.
* Registers are not touched to try to keep this relatively arch
* agnostic.
*/
ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001);
EXPECT_EQ(0, ret);
}
FIXTURE(TRACE_poke) {
struct sock_fprog prog;
pid_t tracer;
long poked;
struct tracer_args_poke_t tracer_args;
};
FIXTURE_SETUP(TRACE_poke)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
self->poked = 0;
memset(&self->prog, 0, sizeof(self->prog));
self->prog.filter = malloc(sizeof(filter));
ASSERT_NE(NULL, self->prog.filter);
memcpy(self->prog.filter, filter, sizeof(filter));
self->prog.len = (unsigned short)ARRAY_SIZE(filter);
/* Set up tracer args. */
self->tracer_args.poke_addr = (unsigned long)&self->poked;
/* Launch tracer. */
self->tracer = setup_trace_fixture(_metadata, tracer_poke,
&self->tracer_args, false);
}
FIXTURE_TEARDOWN(TRACE_poke)
{
teardown_trace_fixture(_metadata, self->tracer);
if (self->prog.filter)
free(self->prog.filter);
}
TEST_F(TRACE_poke, read_has_side_effects)
{
ssize_t ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
ASSERT_EQ(0, ret);
EXPECT_EQ(0, self->poked);
ret = read(-1, NULL, 0);
EXPECT_EQ(-1, ret);
EXPECT_EQ(0x1001, self->poked);
}
TEST_F(TRACE_poke, getpid_runs_normally)
{
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0);
ASSERT_EQ(0, ret);
EXPECT_EQ(0, self->poked);
EXPECT_NE(0, syscall(__NR_getpid));
EXPECT_EQ(0, self->poked);
}
#if defined(__x86_64__)
# define ARCH_REGS struct user_regs_struct
# define SYSCALL_NUM(_regs) (_regs).orig_rax
# define SYSCALL_RET(_regs) (_regs).rax
#elif defined(__i386__)
# define ARCH_REGS struct user_regs_struct
# define SYSCALL_NUM(_regs) (_regs).orig_eax
# define SYSCALL_RET(_regs) (_regs).eax
#elif defined(__arm__)
# define ARCH_REGS struct pt_regs
# define SYSCALL_NUM(_regs) (_regs).ARM_r7
# ifndef PTRACE_SET_SYSCALL
# define PTRACE_SET_SYSCALL 23
# endif
# define SYSCALL_NUM_SET(_regs, _nr) \
EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr))
# define SYSCALL_RET(_regs) (_regs).ARM_r0
#elif defined(__aarch64__)
# define ARCH_REGS struct user_pt_regs
# define SYSCALL_NUM(_regs) (_regs).regs[8]
# ifndef NT_ARM_SYSTEM_CALL
# define NT_ARM_SYSTEM_CALL 0x404
# endif
# define SYSCALL_NUM_SET(_regs, _nr) \
do { \
struct iovec __v; \
typeof(_nr) __nr = (_nr); \
__v.iov_base = &__nr; \
__v.iov_len = sizeof(__nr); \
EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee, \
NT_ARM_SYSTEM_CALL, &__v)); \
} while (0)
# define SYSCALL_RET(_regs) (_regs).regs[0]
#elif defined(__riscv) && __riscv_xlen == 64
# define ARCH_REGS struct user_regs_struct
# define SYSCALL_NUM(_regs) (_regs).a7
# define SYSCALL_RET(_regs) (_regs).a0
#elif defined(__csky__)
# define ARCH_REGS struct pt_regs
# if defined(__CSKYABIV2__)
# define SYSCALL_NUM(_regs) (_regs).regs[3]
# else
# define SYSCALL_NUM(_regs) (_regs).regs[9]
# endif
# define SYSCALL_RET(_regs) (_regs).a0
#elif defined(__hppa__)
# define ARCH_REGS struct user_regs_struct
# define SYSCALL_NUM(_regs) (_regs).gr[20]
# define SYSCALL_RET(_regs) (_regs).gr[28]
#elif defined(__powerpc__)
# define ARCH_REGS struct pt_regs
# define SYSCALL_NUM(_regs) (_regs).gpr[0]
# define SYSCALL_RET(_regs) (_regs).gpr[3]
# define SYSCALL_RET_SET(_regs, _val) \
do { \
typeof(_val) _result = (_val); \
if ((_regs.trap & 0xfff0) == 0x3000) { \
/* \
* scv 0 system call uses -ve result \
* for error, so no need to adjust. \
*/ \
SYSCALL_RET(_regs) = _result; \
} else { \
/* \
* A syscall error is signaled by the \
* CR0 SO bit and the code is stored as \
* a positive value. \
*/ \
if (_result < 0) { \
SYSCALL_RET(_regs) = -_result; \
(_regs).ccr |= 0x10000000; \
} else { \
SYSCALL_RET(_regs) = _result; \
(_regs).ccr &= ~0x10000000; \
} \
} \
} while (0)
# define SYSCALL_RET_SET_ON_PTRACE_EXIT
#elif defined(__s390__)
# define ARCH_REGS s390_regs
# define SYSCALL_NUM(_regs) (_regs).gprs[2]
# define SYSCALL_RET_SET(_regs, _val) \
TH_LOG("Can't modify syscall return on this architecture")
#elif defined(__mips__)
# include <asm/unistd_nr_n32.h>
# include <asm/unistd_nr_n64.h>
# include <asm/unistd_nr_o32.h>
# define ARCH_REGS struct pt_regs
# define SYSCALL_NUM(_regs) \
({ \
typeof((_regs).regs[2]) _nr; \
if ((_regs).regs[2] == __NR_O32_Linux) \
_nr = (_regs).regs[4]; \
else \
_nr = (_regs).regs[2]; \
_nr; \
})
# define SYSCALL_NUM_SET(_regs, _nr) \
do { \
if ((_regs).regs[2] == __NR_O32_Linux) \
(_regs).regs[4] = _nr; \
else \
(_regs).regs[2] = _nr; \
} while (0)
# define SYSCALL_RET_SET(_regs, _val) \
TH_LOG("Can't modify syscall return on this architecture")
#elif defined(__xtensa__)
# define ARCH_REGS struct user_pt_regs
# define SYSCALL_NUM(_regs) (_regs).syscall
/*
* On xtensa syscall return value is in the register
* a2 of the current window which is not fixed.
*/
#define SYSCALL_RET(_regs) (_regs).a[(_regs).windowbase * 4 + 2]
#elif defined(__sh__)
# define ARCH_REGS struct pt_regs
# define SYSCALL_NUM(_regs) (_regs).regs[3]
# define SYSCALL_RET(_regs) (_regs).regs[0]
#else
# error "Do not know how to find your architecture's registers and syscalls"
#endif
/*
* Most architectures can change the syscall by just updating the
* associated register. This is the default if not defined above.
*/
#ifndef SYSCALL_NUM_SET
# define SYSCALL_NUM_SET(_regs, _nr) \
do { \
SYSCALL_NUM(_regs) = (_nr); \
} while (0)
#endif
/*
* Most architectures can change the syscall return value by just
* writing to the SYSCALL_RET register. This is the default if not
* defined above. If an architecture cannot set the return value
* (for example when the syscall and return value register is
* shared), report it with TH_LOG() in an arch-specific definition
* of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined.
*/
#if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET)
# error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch"
#endif
#ifndef SYSCALL_RET_SET
# define SYSCALL_RET_SET(_regs, _val) \
do { \
SYSCALL_RET(_regs) = (_val); \
} while (0)
#endif
/* When the syscall return can't be changed, stub out the tests for it. */
#ifndef SYSCALL_RET
# define EXPECT_SYSCALL_RETURN(val, action) EXPECT_EQ(-1, action)
#else
# define EXPECT_SYSCALL_RETURN(val, action) \
do { \
errno = 0; \
if (val < 0) { \
EXPECT_EQ(-1, action); \
EXPECT_EQ(-(val), errno); \
} else { \
EXPECT_EQ(val, action); \
} \
} while (0)
#endif
/*
* Some architectures (e.g. powerpc) can only set syscall
* return values on syscall exit during ptrace.
*/
const bool ptrace_entry_set_syscall_nr = true;
const bool ptrace_entry_set_syscall_ret =
#ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT
true;
#else
false;
#endif
/*
* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
* architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
*/
#if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
# define ARCH_GETREGS(_regs) ptrace(PTRACE_GETREGS, tracee, 0, &(_regs))
# define ARCH_SETREGS(_regs) ptrace(PTRACE_SETREGS, tracee, 0, &(_regs))
#else
# define ARCH_GETREGS(_regs) ({ \
struct iovec __v; \
__v.iov_base = &(_regs); \
__v.iov_len = sizeof(_regs); \
ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v); \
})
# define ARCH_SETREGS(_regs) ({ \
struct iovec __v; \
__v.iov_base = &(_regs); \
__v.iov_len = sizeof(_regs); \
ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v); \
})
#endif
/* Architecture-specific syscall fetching routine. */
int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
{
ARCH_REGS regs;
EXPECT_EQ(0, ARCH_GETREGS(regs)) {
return -1;
}
return SYSCALL_NUM(regs);
}
/* Architecture-specific syscall changing routine. */
void __change_syscall(struct __test_metadata *_metadata,
pid_t tracee, long *syscall, long *ret)
{
ARCH_REGS orig, regs;
/* Do not get/set registers if we have nothing to do. */
if (!syscall && !ret)
return;
EXPECT_EQ(0, ARCH_GETREGS(regs)) {
return;
}
orig = regs;
if (syscall)
SYSCALL_NUM_SET(regs, *syscall);
if (ret)
SYSCALL_RET_SET(regs, *ret);
/* Flush any register changes made. */
if (memcmp(&orig, &regs, sizeof(orig)) != 0)
EXPECT_EQ(0, ARCH_SETREGS(regs));
}
/* Change only syscall number. */
void change_syscall_nr(struct __test_metadata *_metadata,
pid_t tracee, long syscall)
{
__change_syscall(_metadata, tracee, &syscall, NULL);
}
/* Change syscall return value (and set syscall number to -1). */
void change_syscall_ret(struct __test_metadata *_metadata,
pid_t tracee, long ret)
{
long syscall = -1;
__change_syscall(_metadata, tracee, &syscall, &ret);
}
void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
int status, void *args)
{
int ret;
unsigned long msg;
EXPECT_EQ(PTRACE_EVENT_MASK(status), PTRACE_EVENT_SECCOMP) {
TH_LOG("Unexpected ptrace event: %d", PTRACE_EVENT_MASK(status));
return;
}
/* Make sure we got the right message. */
ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
EXPECT_EQ(0, ret);
/* Validate and take action on expected syscalls. */
switch (msg) {
case 0x1002:
/* change getpid to getppid. */
EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
change_syscall_nr(_metadata, tracee, __NR_getppid);
break;
case 0x1003:
/* skip gettid with valid return code. */
EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
change_syscall_ret(_metadata, tracee, 45000);
break;
case 0x1004:
/* skip openat with error. */
EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
change_syscall_ret(_metadata, tracee, -ESRCH);
break;
case 0x1005:
/* do nothing (allow getppid) */
EXPECT_EQ(__NR_getppid, get_syscall(_metadata, tracee));
break;
default:
EXPECT_EQ(0, msg) {
TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg);
kill(tracee, SIGKILL);
}
}
}
FIXTURE(TRACE_syscall) {
struct sock_fprog prog;
pid_t tracer, mytid, mypid, parent;
long syscall_nr;
};
void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
int status, void *args)
{
int ret;
unsigned long msg;
static bool entry;
long syscall_nr_val, syscall_ret_val;
long *syscall_nr = NULL, *syscall_ret = NULL;
FIXTURE_DATA(TRACE_syscall) *self = args;
EXPECT_EQ(WSTOPSIG(status) & 0x80, 0x80) {
TH_LOG("Unexpected WSTOPSIG: %d", WSTOPSIG(status));
return;
}
/*
* The traditional way to tell PTRACE_SYSCALL entry/exit
* is by counting.
*/
entry = !entry;
/* Make sure we got an appropriate message. */
ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg);
EXPECT_EQ(0, ret);
EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
: PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
/*
* Some architectures only support setting return values during
* syscall exit under ptrace, and on exit the syscall number may
* no longer be available. Therefore, save the initial sycall
* number here, so it can be examined during both entry and exit
* phases.
*/
if (entry)
self->syscall_nr = get_syscall(_metadata, tracee);
/*
* Depending on the architecture's syscall setting abilities, we
* pick which things to set during this phase (entry or exit).
*/
if (entry == ptrace_entry_set_syscall_nr)
syscall_nr = &syscall_nr_val;
if (entry == ptrace_entry_set_syscall_ret)
syscall_ret = &syscall_ret_val;
/* Now handle the actual rewriting cases. */
switch (self->syscall_nr) {
case __NR_getpid:
syscall_nr_val = __NR_getppid;
/* Never change syscall return for this case. */
syscall_ret = NULL;
break;
case __NR_gettid:
syscall_nr_val = -1;
syscall_ret_val = 45000;
break;
case __NR_openat:
syscall_nr_val = -1;
syscall_ret_val = -ESRCH;
break;
default:
/* Unhandled, do nothing. */
return;
}
__change_syscall(_metadata, tracee, syscall_nr, syscall_ret);
}
FIXTURE_VARIANT(TRACE_syscall) {
/*
* All of the SECCOMP_RET_TRACE behaviors can be tested with either
* SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL.
* This indicates if we should use SECCOMP_RET_TRACE (false), or
* ptrace (true).
*/
bool use_ptrace;
};
FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) {
.use_ptrace = true,
};
FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) {
.use_ptrace = false,
};
FIXTURE_SETUP(TRACE_syscall)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_openat, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
/* Prepare some testable syscall results. */
self->mytid = syscall(__NR_gettid);
ASSERT_GT(self->mytid, 0);
ASSERT_NE(self->mytid, 1) {
TH_LOG("Running this test as init is not supported. :)");
}
self->mypid = getpid();
ASSERT_GT(self->mypid, 0);
ASSERT_EQ(self->mytid, self->mypid);
self->parent = getppid();
ASSERT_GT(self->parent, 0);
ASSERT_NE(self->parent, self->mypid);
/* Launch tracer. */
self->tracer = setup_trace_fixture(_metadata,
variant->use_ptrace ? tracer_ptrace
: tracer_seccomp,
self, variant->use_ptrace);
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
/* Do not install seccomp rewrite filters, as we'll use ptrace instead. */
if (variant->use_ptrace)
return;
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_EQ(0, ret);
}
FIXTURE_TEARDOWN(TRACE_syscall)
{
teardown_trace_fixture(_metadata, self->tracer);
}
TEST(negative_ENOSYS)
{
/*
* There should be no difference between an "internal" skip
* and userspace asking for syscall "-1".
*/
errno = 0;
EXPECT_EQ(-1, syscall(-1));
EXPECT_EQ(errno, ENOSYS);
/* And no difference for "still not valid but not -1". */
errno = 0;
EXPECT_EQ(-1, syscall(-101));
EXPECT_EQ(errno, ENOSYS);
}
TEST_F(TRACE_syscall, negative_ENOSYS)
{
negative_ENOSYS(_metadata);
}
TEST_F(TRACE_syscall, syscall_allowed)
{
/* getppid works as expected (no changes). */
EXPECT_EQ(self->parent, syscall(__NR_getppid));
EXPECT_NE(self->mypid, syscall(__NR_getppid));
}
TEST_F(TRACE_syscall, syscall_redirected)
{
/* getpid has been redirected to getppid as expected. */
EXPECT_EQ(self->parent, syscall(__NR_getpid));
EXPECT_NE(self->mypid, syscall(__NR_getpid));
}
TEST_F(TRACE_syscall, syscall_errno)
{
/* Tracer should skip the open syscall, resulting in ESRCH. */
EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat));
}
TEST_F(TRACE_syscall, syscall_faked)
{
/* Tracer skips the gettid syscall and store altered return value. */
EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid));
}
TEST_F_SIGNAL(TRACE_syscall, kill_immediate, SIGSYS)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_mknodat, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
/* Install "kill on mknodat" filter. */
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_EQ(0, ret);
/* This should immediately die with SIGSYS, regardless of tracer. */
EXPECT_EQ(-1, syscall(__NR_mknodat, -1, NULL, 0, 0));
}
TEST_F(TRACE_syscall, skip_after)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
/* Install additional "errno on getppid" filter. */
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_EQ(0, ret);
/* Tracer will redirect getpid to getppid, and we should see EPERM. */
errno = 0;
EXPECT_EQ(-1, syscall(__NR_getpid));
EXPECT_EQ(EPERM, errno);
}
TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
/* Install additional "death on getppid" filter. */
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
ASSERT_EQ(0, ret);
/* Tracer will redirect getpid to getppid, and we should die. */
EXPECT_NE(self->mypid, syscall(__NR_getpid));
}
TEST(seccomp_syscall)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
/* Reject insane operation. */
ret = seccomp(-1, 0, &prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Did not reject crazy op value!");
}
/* Reject strict with flags or pointer. */
ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL);
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Did not reject mode strict with flags!");
}
ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog);
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Did not reject mode strict with uargs!");
}
/* Reject insane args for filter. */
ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog);
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Did not reject crazy filter flags!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL);
EXPECT_EQ(EFAULT, errno) {
TH_LOG("Did not reject NULL filter!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
EXPECT_EQ(0, errno) {
TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s",
strerror(errno));
}
}
TEST(seccomp_syscall_mode_lock)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
EXPECT_EQ(0, ret) {
TH_LOG("Could not install filter!");
}
/* Make sure neither entry point will switch to strict. */
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0);
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Switched to mode strict!");
}
ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL);
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Switched to mode strict!");
}
}
/*
* Test detection of known and unknown filter flags. Userspace needs to be able
* to check if a filter flag is supported by the current kernel and a good way
* of doing that is by attempting to enter filter mode, with the flag bit in
* question set, and a NULL pointer for the _args_ parameter. EFAULT indicates
* that the flag is valid and EINVAL indicates that the flag is invalid.
*/
TEST(detect_seccomp_filter_flags)
{
unsigned int flags[] = { SECCOMP_FILTER_FLAG_TSYNC,
SECCOMP_FILTER_FLAG_LOG,
SECCOMP_FILTER_FLAG_SPEC_ALLOW,
SECCOMP_FILTER_FLAG_NEW_LISTENER,
SECCOMP_FILTER_FLAG_TSYNC_ESRCH };
unsigned int exclusive[] = {
SECCOMP_FILTER_FLAG_TSYNC,
SECCOMP_FILTER_FLAG_NEW_LISTENER };
unsigned int flag, all_flags, exclusive_mask;
int i;
long ret;
/* Test detection of individual known-good filter flags */
for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
int bits = 0;
flag = flags[i];
/* Make sure the flag is a single bit! */
while (flag) {
if (flag & 0x1)
bits ++;
flag >>= 1;
}
ASSERT_EQ(1, bits);
flag = flags[i];
ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
EXPECT_EQ(-1, ret);
EXPECT_EQ(EFAULT, errno) {
TH_LOG("Failed to detect that a known-good filter flag (0x%X) is supported!",
flag);
}
all_flags |= flag;
}
/*
* Test detection of all known-good filter flags combined. But
* for the exclusive flags we need to mask them out and try them
* individually for the "all flags" testing.
*/
exclusive_mask = 0;
for (i = 0; i < ARRAY_SIZE(exclusive); i++)
exclusive_mask |= exclusive[i];
for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
flag = all_flags & ~exclusive_mask;
flag |= exclusive[i];
ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EFAULT, errno) {
TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
flag);
}
}
/* Test detection of an unknown filter flags, without exclusives. */
flag = -1;
flag &= ~exclusive_mask;
ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported!",
flag);
}
/*
* Test detection of an unknown filter flag that may simply need to be
* added to this test
*/
flag = flags[ARRAY_SIZE(flags) - 1] << 1;
ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Failed to detect that an unknown filter flag (0x%X) is unsupported! Does a new flag need to be added to this test?",
flag);
}
}
TEST(TSYNC_first)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
long ret;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
&prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
EXPECT_EQ(0, ret) {
TH_LOG("Could not install initial filter with TSYNC!");
}
}
#define TSYNC_SIBLINGS 2
struct tsync_sibling {
pthread_t tid;
pid_t system_tid;
sem_t *started;
pthread_cond_t *cond;
pthread_mutex_t *mutex;
int diverge;
int num_waits;
struct sock_fprog *prog;
struct __test_metadata *metadata;
};
/*
* To avoid joining joined threads (which is not allowed by Bionic),
* make sure we both successfully join and clear the tid to skip a
* later join attempt during fixture teardown. Any remaining threads
* will be directly killed during teardown.
*/
#define PTHREAD_JOIN(tid, status) \
do { \
int _rc = pthread_join(tid, status); \
if (_rc) { \
TH_LOG("pthread_join of tid %u failed: %d\n", \
(unsigned int)tid, _rc); \
} else { \
tid = 0; \
} \
} while (0)
FIXTURE(TSYNC) {
struct sock_fprog root_prog, apply_prog;
struct tsync_sibling sibling[TSYNC_SIBLINGS];
sem_t started;
pthread_cond_t cond;
pthread_mutex_t mutex;
int sibling_count;
};
FIXTURE_SETUP(TSYNC)
{
struct sock_filter root_filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_filter apply_filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
memset(&self->root_prog, 0, sizeof(self->root_prog));
memset(&self->apply_prog, 0, sizeof(self->apply_prog));
memset(&self->sibling, 0, sizeof(self->sibling));
self->root_prog.filter = malloc(sizeof(root_filter));
ASSERT_NE(NULL, self->root_prog.filter);
memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter));
self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter);
self->apply_prog.filter = malloc(sizeof(apply_filter));
ASSERT_NE(NULL, self->apply_prog.filter);
memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter));
self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter);
self->sibling_count = 0;
pthread_mutex_init(&self->mutex, NULL);
pthread_cond_init(&self->cond, NULL);
sem_init(&self->started, 0, 0);
self->sibling[0].tid = 0;
self->sibling[0].cond = &self->cond;
self->sibling[0].started = &self->started;
self->sibling[0].mutex = &self->mutex;
self->sibling[0].diverge = 0;
self->sibling[0].num_waits = 1;
self->sibling[0].prog = &self->root_prog;
self->sibling[0].metadata = _metadata;
self->sibling[1].tid = 0;
self->sibling[1].cond = &self->cond;
self->sibling[1].started = &self->started;
self->sibling[1].mutex = &self->mutex;
self->sibling[1].diverge = 0;
self->sibling[1].prog = &self->root_prog;
self->sibling[1].num_waits = 1;
self->sibling[1].metadata = _metadata;
}
FIXTURE_TEARDOWN(TSYNC)
{
int sib = 0;
if (self->root_prog.filter)
free(self->root_prog.filter);
if (self->apply_prog.filter)
free(self->apply_prog.filter);
for ( ; sib < self->sibling_count; ++sib) {
struct tsync_sibling *s = &self->sibling[sib];
if (!s->tid)
continue;
/*
* If a thread is still running, it may be stuck, so hit
* it over the head really hard.
*/
pthread_kill(s->tid, 9);
}
pthread_mutex_destroy(&self->mutex);
pthread_cond_destroy(&self->cond);
sem_destroy(&self->started);
}
void *tsync_sibling(void *data)
{
long ret = 0;
struct tsync_sibling *me = data;
me->system_tid = syscall(__NR_gettid);
pthread_mutex_lock(me->mutex);
if (me->diverge) {
/* Just re-apply the root prog to fork the tree */
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER,
me->prog, 0, 0);
}
sem_post(me->started);
/* Return outside of started so parent notices failures. */
if (ret) {
pthread_mutex_unlock(me->mutex);
return (void *)SIBLING_EXIT_FAILURE;
}
do {
pthread_cond_wait(me->cond, me->mutex);
me->num_waits = me->num_waits - 1;
} while (me->num_waits);
pthread_mutex_unlock(me->mutex);
ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
if (!ret)
return (void *)SIBLING_EXIT_NEWPRIVS;
read(-1, NULL, 0);
return (void *)SIBLING_EXIT_UNKILLED;
}
void tsync_start_sibling(struct tsync_sibling *sibling)
{
pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling);
}
TEST_F(TSYNC, siblings_fail_prctl)
{
long ret;
void *status;
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
/* Check prctl failure detection by requesting sib 0 diverge. */
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
ASSERT_EQ(0, ret) {
TH_LOG("setting filter failed");
}
self->sibling[0].diverge = 1;
tsync_start_sibling(&self->sibling[0]);
tsync_start_sibling(&self->sibling[1]);
while (self->sibling_count < TSYNC_SIBLINGS) {
sem_wait(&self->started);
self->sibling_count++;
}
/* Signal the threads to clean up*/
pthread_mutex_lock(&self->mutex);
ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
TH_LOG("cond broadcast non-zero");
}
pthread_mutex_unlock(&self->mutex);
/* Ensure diverging sibling failed to call prctl. */
PTHREAD_JOIN(self->sibling[0].tid, &status);
EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status);
PTHREAD_JOIN(self->sibling[1].tid, &status);
EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
}
TEST_F(TSYNC, two_siblings_with_ancestor)
{
long ret;
void *status;
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
}
tsync_start_sibling(&self->sibling[0]);
tsync_start_sibling(&self->sibling[1]);
while (self->sibling_count < TSYNC_SIBLINGS) {
sem_wait(&self->started);
self->sibling_count++;
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
&self->apply_prog);
ASSERT_EQ(0, ret) {
TH_LOG("Could install filter on all threads!");
}
/* Tell the siblings to test the policy */
pthread_mutex_lock(&self->mutex);
ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
TH_LOG("cond broadcast non-zero");
}
pthread_mutex_unlock(&self->mutex);
/* Ensure they are both killed and don't exit cleanly. */
PTHREAD_JOIN(self->sibling[0].tid, &status);
EXPECT_EQ(0x0, (long)status);
PTHREAD_JOIN(self->sibling[1].tid, &status);
EXPECT_EQ(0x0, (long)status);
}
TEST_F(TSYNC, two_sibling_want_nnp)
{
void *status;
/* start siblings before any prctl() operations */
tsync_start_sibling(&self->sibling[0]);
tsync_start_sibling(&self->sibling[1]);
while (self->sibling_count < TSYNC_SIBLINGS) {
sem_wait(&self->started);
self->sibling_count++;
}
/* Tell the siblings to test no policy */
pthread_mutex_lock(&self->mutex);
ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
TH_LOG("cond broadcast non-zero");
}
pthread_mutex_unlock(&self->mutex);
/* Ensure they are both upset about lacking nnp. */
PTHREAD_JOIN(self->sibling[0].tid, &status);
EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
PTHREAD_JOIN(self->sibling[1].tid, &status);
EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status);
}
TEST_F(TSYNC, two_siblings_with_no_filter)
{
long ret;
void *status;
/* start siblings before any prctl() operations */
tsync_start_sibling(&self->sibling[0]);
tsync_start_sibling(&self->sibling[1]);
while (self->sibling_count < TSYNC_SIBLINGS) {
sem_wait(&self->started);
self->sibling_count++;
}
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
&self->apply_prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
ASSERT_EQ(0, ret) {
TH_LOG("Could install filter on all threads!");
}
/* Tell the siblings to test the policy */
pthread_mutex_lock(&self->mutex);
ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
TH_LOG("cond broadcast non-zero");
}
pthread_mutex_unlock(&self->mutex);
/* Ensure they are both killed and don't exit cleanly. */
PTHREAD_JOIN(self->sibling[0].tid, &status);
EXPECT_EQ(0x0, (long)status);
PTHREAD_JOIN(self->sibling[1].tid, &status);
EXPECT_EQ(0x0, (long)status);
}
TEST_F(TSYNC, two_siblings_with_one_divergence)
{
long ret;
void *status;
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
}
self->sibling[0].diverge = 1;
tsync_start_sibling(&self->sibling[0]);
tsync_start_sibling(&self->sibling[1]);
while (self->sibling_count < TSYNC_SIBLINGS) {
sem_wait(&self->started);
self->sibling_count++;
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
&self->apply_prog);
ASSERT_EQ(self->sibling[0].system_tid, ret) {
TH_LOG("Did not fail on diverged sibling.");
}
/* Wake the threads */
pthread_mutex_lock(&self->mutex);
ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
TH_LOG("cond broadcast non-zero");
}
pthread_mutex_unlock(&self->mutex);
/* Ensure they are both unkilled. */
PTHREAD_JOIN(self->sibling[0].tid, &status);
EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
PTHREAD_JOIN(self->sibling[1].tid, &status);
EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
}
TEST_F(TSYNC, two_siblings_with_one_divergence_no_tid_in_err)
{
long ret, flags;
void *status;
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
}
self->sibling[0].diverge = 1;
tsync_start_sibling(&self->sibling[0]);
tsync_start_sibling(&self->sibling[1]);
while (self->sibling_count < TSYNC_SIBLINGS) {
sem_wait(&self->started);
self->sibling_count++;
}
flags = SECCOMP_FILTER_FLAG_TSYNC | \
SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
ret = seccomp(SECCOMP_SET_MODE_FILTER, flags, &self->apply_prog);
ASSERT_EQ(ESRCH, errno) {
TH_LOG("Did not return ESRCH for diverged sibling.");
}
ASSERT_EQ(-1, ret) {
TH_LOG("Did not fail on diverged sibling.");
}
/* Wake the threads */
pthread_mutex_lock(&self->mutex);
ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
TH_LOG("cond broadcast non-zero");
}
pthread_mutex_unlock(&self->mutex);
/* Ensure they are both unkilled. */
PTHREAD_JOIN(self->sibling[0].tid, &status);
EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
PTHREAD_JOIN(self->sibling[1].tid, &status);
EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
}
TEST_F(TSYNC, two_siblings_not_under_filter)
{
long ret, sib;
void *status;
struct timespec delay = { .tv_nsec = 100000000 };
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
/*
* Sibling 0 will have its own seccomp policy
* and Sibling 1 will not be under seccomp at
* all. Sibling 1 will enter seccomp and 0
* will cause failure.
*/
self->sibling[0].diverge = 1;
tsync_start_sibling(&self->sibling[0]);
tsync_start_sibling(&self->sibling[1]);
while (self->sibling_count < TSYNC_SIBLINGS) {
sem_wait(&self->started);
self->sibling_count++;
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!");
}
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
&self->apply_prog);
ASSERT_EQ(ret, self->sibling[0].system_tid) {
TH_LOG("Did not fail on diverged sibling.");
}
sib = 1;
if (ret == self->sibling[0].system_tid)
sib = 0;
pthread_mutex_lock(&self->mutex);
/* Increment the other siblings num_waits so we can clean up
* the one we just saw.
*/
self->sibling[!sib].num_waits += 1;
/* Signal the thread to clean up*/
ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
TH_LOG("cond broadcast non-zero");
}
pthread_mutex_unlock(&self->mutex);
PTHREAD_JOIN(self->sibling[sib].tid, &status);
EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status);
/* Poll for actual task death. pthread_join doesn't guarantee it. */
while (!kill(self->sibling[sib].system_tid, 0))
nanosleep(&delay, NULL);
/* Switch to the remaining sibling */
sib = !sib;
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
&self->apply_prog);
ASSERT_EQ(0, ret) {
TH_LOG("Expected the remaining sibling to sync");
};
pthread_mutex_lock(&self->mutex);
/* If remaining sibling didn't have a chance to wake up during
* the first broadcast, manually reduce the num_waits now.
*/
if (self->sibling[sib].num_waits > 1)
self->sibling[sib].num_waits = 1;
ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) {
TH_LOG("cond broadcast non-zero");
}
pthread_mutex_unlock(&self->mutex);
PTHREAD_JOIN(self->sibling[sib].tid, &status);
EXPECT_EQ(0, (long)status);
/* Poll for actual task death. pthread_join doesn't guarantee it. */
while (!kill(self->sibling[sib].system_tid, 0))
nanosleep(&delay, NULL);
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
&self->apply_prog);
ASSERT_EQ(0, ret); /* just us chickens */
}
/* Make sure restarted syscalls are seen directly as "restart_syscall". */
TEST(syscall_restart)
{
long ret;
unsigned long msg;
pid_t child_pid;
int pipefd[2];
int status;
siginfo_t info = { };
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
#ifdef __NR_sigreturn
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 7, 0),
#endif
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 6, 0),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 5, 0),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 4, 0),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_nanosleep, 5, 0),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_clock_nanosleep, 4, 0),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0),
/* Allow __NR_write for easy logging. */
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
/* The nanosleep jump target. */
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100),
/* The restart_syscall jump target. */
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
#if defined(__arm__)
struct utsname utsbuf;
#endif
ASSERT_EQ(0, pipe(pipefd));
child_pid = fork();
ASSERT_LE(0, child_pid);
if (child_pid == 0) {
/* Child uses EXPECT not ASSERT to deliver status correctly. */
char buf = ' ';
struct timespec timeout = { };
/* Attach parent as tracer and stop. */
EXPECT_EQ(0, ptrace(PTRACE_TRACEME));
EXPECT_EQ(0, raise(SIGSTOP));
EXPECT_EQ(0, close(pipefd[1]));
EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0);
EXPECT_EQ(0, ret) {
TH_LOG("Failed to install filter!");
}
EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
TH_LOG("Failed to read() sync from parent");
}
EXPECT_EQ('.', buf) {
TH_LOG("Failed to get sync data from read()");
}
/* Start nanosleep to be interrupted. */
timeout.tv_sec = 1;
errno = 0;
EXPECT_EQ(0, nanosleep(&timeout, NULL)) {
TH_LOG("Call to nanosleep() failed (errno %d)", errno);
}
/* Read final sync from parent. */
EXPECT_EQ(1, read(pipefd[0], &buf, 1)) {
TH_LOG("Failed final read() from parent");
}
EXPECT_EQ('!', buf) {
TH_LOG("Failed to get final data from read()");
}
/* Directly report the status of our test harness results. */
syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS
: EXIT_FAILURE);
}
EXPECT_EQ(0, close(pipefd[0]));
/* Attach to child, setup options, and release. */
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
ASSERT_EQ(true, WIFSTOPPED(status));
ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL,
PTRACE_O_TRACESECCOMP));
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
ASSERT_EQ(1, write(pipefd[1], ".", 1));
/* Wait for nanosleep() to start. */
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
ASSERT_EQ(true, WIFSTOPPED(status));
ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
ASSERT_EQ(0x100, msg);
ret = get_syscall(_metadata, child_pid);
EXPECT_TRUE(ret == __NR_nanosleep || ret == __NR_clock_nanosleep);
/* Might as well check siginfo for sanity while we're here. */
ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
ASSERT_EQ(SIGTRAP, info.si_signo);
ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code);
EXPECT_EQ(0, info.si_errno);
EXPECT_EQ(getuid(), info.si_uid);
/* Verify signal delivery came from child (seccomp-triggered). */
EXPECT_EQ(child_pid, info.si_pid);
/* Interrupt nanosleep with SIGSTOP (which we'll need to handle). */
ASSERT_EQ(0, kill(child_pid, SIGSTOP));
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
ASSERT_EQ(true, WIFSTOPPED(status));
ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));
/*
* There is no siginfo on SIGSTOP any more, so we can't verify
* signal delivery came from parent now (getpid() == info.si_pid).
* https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com
* At least verify the SIGSTOP via PTRACE_GETSIGINFO.
*/
EXPECT_EQ(SIGSTOP, info.si_signo);
/* Restart nanosleep with SIGCONT, which triggers restart_syscall. */
ASSERT_EQ(0, kill(child_pid, SIGCONT));
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
ASSERT_EQ(true, WIFSTOPPED(status));
ASSERT_EQ(SIGCONT, WSTOPSIG(status));
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
/* Wait for restart_syscall() to start. */
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
ASSERT_EQ(true, WIFSTOPPED(status));
ASSERT_EQ(SIGTRAP, WSTOPSIG(status));
ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16));
ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg));
ASSERT_EQ(0x200, msg);
ret = get_syscall(_metadata, child_pid);
#if defined(__arm__)
/*
* FIXME:
* - native ARM registers do NOT expose true syscall.
* - compat ARM registers on ARM64 DO expose true syscall.
*/
ASSERT_EQ(0, uname(&utsbuf));
if (strncmp(utsbuf.machine, "arm", 3) == 0) {
EXPECT_EQ(__NR_nanosleep, ret);
} else
#endif
{
EXPECT_EQ(__NR_restart_syscall, ret);
}
/* Write again to end test. */
ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0));
ASSERT_EQ(1, write(pipefd[1], "!", 1));
EXPECT_EQ(0, close(pipefd[1]));
ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
if (WIFSIGNALED(status) || WEXITSTATUS(status))
_metadata->passed = 0;
}
TEST_SIGNAL(filter_flag_log, SIGSYS)
{
struct sock_filter allow_filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_filter kill_filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog allow_prog = {
.len = (unsigned short)ARRAY_SIZE(allow_filter),
.filter = allow_filter,
};
struct sock_fprog kill_prog = {
.len = (unsigned short)ARRAY_SIZE(kill_filter),
.filter = kill_filter,
};
long ret;
pid_t parent = getppid();
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret);
/* Verify that the FILTER_FLAG_LOG flag isn't accepted in strict mode */
ret = seccomp(SECCOMP_SET_MODE_STRICT, SECCOMP_FILTER_FLAG_LOG,
&allow_prog);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
EXPECT_NE(0, ret) {
TH_LOG("Kernel accepted FILTER_FLAG_LOG flag in strict mode!");
}
EXPECT_EQ(EINVAL, errno) {
TH_LOG("Kernel returned unexpected errno for FILTER_FLAG_LOG flag in strict mode!");
}
/* Verify that a simple, permissive filter can be added with no flags */
ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog);
EXPECT_EQ(0, ret);
/* See if the same filter can be added with the FILTER_FLAG_LOG flag */
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
&allow_prog);
ASSERT_NE(EINVAL, errno) {
TH_LOG("Kernel does not support the FILTER_FLAG_LOG flag!");
}
EXPECT_EQ(0, ret);
/* Ensure that the kill filter works with the FILTER_FLAG_LOG flag */
ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_LOG,
&kill_prog);
EXPECT_EQ(0, ret);
EXPECT_EQ(parent, syscall(__NR_getppid));
/* getpid() should never return. */
EXPECT_EQ(0, syscall(__NR_getpid));
}
TEST(get_action_avail)
{
__u32 actions[] = { SECCOMP_RET_KILL_THREAD, SECCOMP_RET_TRAP,
SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE,
SECCOMP_RET_LOG, SECCOMP_RET_ALLOW };
__u32 unknown_action = 0x10000000U;
int i;
long ret;
ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[0]);
ASSERT_NE(ENOSYS, errno) {
TH_LOG("Kernel does not support seccomp syscall!");
}
ASSERT_NE(EINVAL, errno) {
TH_LOG("Kernel does not support SECCOMP_GET_ACTION_AVAIL operation!");
}
EXPECT_EQ(ret, 0);
for (i = 0; i < ARRAY_SIZE(actions); i++) {
ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &actions[i]);
EXPECT_EQ(ret, 0) {
TH_LOG("Expected action (0x%X) not available!",
actions[i]);
}
}
/* Check that an unknown action is handled properly (EOPNOTSUPP) */
ret = seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &unknown_action);
EXPECT_EQ(ret, -1);
EXPECT_EQ(errno, EOPNOTSUPP);
}
TEST(get_metadata)
{
pid_t pid;
int pipefd[2];
char buf;
struct seccomp_metadata md;
long ret;
/* Only real root can get metadata. */
if (geteuid()) {
SKIP(return, "get_metadata requires real root");
return;
}
ASSERT_EQ(0, pipe(pipefd));
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
/* one with log, one without */
EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
SECCOMP_FILTER_FLAG_LOG, &prog));
EXPECT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
EXPECT_EQ(0, close(pipefd[0]));
ASSERT_EQ(1, write(pipefd[1], "1", 1));
ASSERT_EQ(0, close(pipefd[1]));
while (1)
sleep(100);
}
ASSERT_EQ(0, close(pipefd[1]));
ASSERT_EQ(1, read(pipefd[0], &buf, 1));
ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
ASSERT_EQ(pid, waitpid(pid, NULL, 0));
/* Past here must not use ASSERT or child process is never killed. */
md.filter_off = 0;
errno = 0;
ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
EXPECT_EQ(sizeof(md), ret) {
if (errno == EINVAL)
SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)");
}
EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
EXPECT_EQ(md.filter_off, 0);
md.filter_off = 1;
ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md);
EXPECT_EQ(sizeof(md), ret);
EXPECT_EQ(md.flags, 0);
EXPECT_EQ(md.filter_off, 1);
skip:
ASSERT_EQ(0, kill(pid, SIGKILL));
}
static int user_notif_syscall(int nr, unsigned int flags)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
offsetof(struct seccomp_data, nr)),
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF),
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
return seccomp(SECCOMP_SET_MODE_FILTER, flags, &prog);
}
#define USER_NOTIF_MAGIC INT_MAX
TEST(user_notification_basic)
{
pid_t pid;
long ret;
int status, listener;
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
struct pollfd pollfd;
struct sock_filter filter[] = {
BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)ARRAY_SIZE(filter),
.filter = filter,
};
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
pid = fork();
ASSERT_GE(pid, 0);
/* Check that we get -ENOSYS with no listener attached */
if (pid == 0) {
if (user_notif_syscall(__NR_getppid, 0) < 0)
exit(1);
ret = syscall(__NR_getppid);
exit(ret >= 0 || errno != ENOSYS);
}
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
/* Add some no-op filters for grins. */
EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0);
/* Check that the basic notification machinery works */
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
/* Installing a second listener in the chain should EBUSY */
EXPECT_EQ(user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER),
-1);
EXPECT_EQ(errno, EBUSY);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
ret = syscall(__NR_getppid);
exit(ret != USER_NOTIF_MAGIC);
}
pollfd.fd = listener;
pollfd.events = POLLIN | POLLOUT;
EXPECT_GT(poll(&pollfd, 1, -1), 0);
EXPECT_EQ(pollfd.revents, POLLIN);
/* Test that we can't pass garbage to the kernel. */
memset(&req, 0, sizeof(req));
req.pid = -1;
errno = 0;
ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EINVAL, errno);
if (ret) {
req.pid = 0;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
}
pollfd.fd = listener;
pollfd.events = POLLIN | POLLOUT;
EXPECT_GT(poll(&pollfd, 1, -1), 0);
EXPECT_EQ(pollfd.revents, POLLOUT);
EXPECT_EQ(req.data.nr, __NR_getppid);
resp.id = req.id;
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
/* check that we make sure flags == 0 */
resp.flags = 1;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
EXPECT_EQ(errno, EINVAL);
resp.flags = 0;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
}
TEST(user_notification_with_tsync)
{
int ret;
unsigned int flags;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
/* these were exclusive */
flags = SECCOMP_FILTER_FLAG_NEW_LISTENER |
SECCOMP_FILTER_FLAG_TSYNC;
ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags));
ASSERT_EQ(EINVAL, errno);
/* but now they're not */
flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH;
ret = user_notif_syscall(__NR_getppid, flags);
close(ret);
ASSERT_LE(0, ret);
}
TEST(user_notification_kill_in_middle)
{
pid_t pid;
long ret;
int listener;
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
/*
* Check that nothing bad happens when we kill the task in the middle
* of a syscall.
*/
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
ret = syscall(__NR_getppid);
exit(ret != USER_NOTIF_MAGIC);
}
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), 0);
EXPECT_EQ(kill(pid, SIGKILL), 0);
EXPECT_EQ(waitpid(pid, NULL, 0), pid);
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ID_VALID, &req.id), -1);
resp.id = req.id;
ret = ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp);
EXPECT_EQ(ret, -1);
EXPECT_EQ(errno, ENOENT);
}
static int handled = -1;
static void signal_handler(int signal)
{
if (write(handled, "c", 1) != 1)
perror("write from signal");
}
TEST(user_notification_signal)
{
pid_t pid;
long ret;
int status, listener, sk_pair[2];
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
char c;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
listener = user_notif_syscall(__NR_gettid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
close(sk_pair[0]);
handled = sk_pair[1];
if (signal(SIGUSR1, signal_handler) == SIG_ERR) {
perror("signal");
exit(1);
}
/*
* ERESTARTSYS behavior is a bit hard to test, because we need
* to rely on a signal that has not yet been handled. Let's at
* least check that the error code gets propagated through, and
* hope that it doesn't break when there is actually a signal :)
*/
ret = syscall(__NR_gettid);
exit(!(ret == -1 && errno == 512));
}
close(sk_pair[1]);
memset(&req, 0, sizeof(req));
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
EXPECT_EQ(kill(pid, SIGUSR1), 0);
/*
* Make sure the signal really is delivered, which means we're not
* stuck in the user notification code any more and the notification
* should be dead.
*/
EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
resp.id = req.id;
resp.error = -EPERM;
resp.val = 0;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
EXPECT_EQ(errno, ENOENT);
memset(&req, 0, sizeof(req));
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
resp.id = req.id;
resp.error = -512; /* -ERESTARTSYS */
resp.val = 0;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
}
TEST(user_notification_closed_listener)
{
pid_t pid;
long ret;
int status, listener;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
/*
* Check that we get an ENOSYS when the listener is closed.
*/
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
close(listener);
ret = syscall(__NR_getppid);
exit(ret != -1 && errno != ENOSYS);
}
close(listener);
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
}
/*
* Check that a pid in a child namespace still shows up as valid in ours.
*/
TEST(user_notification_child_pid_ns)
{
pid_t pid;
int status, listener;
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) {
if (errno == EINVAL)
SKIP(return, "kernel missing CLONE_NEWUSER support");
};
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0)
exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
EXPECT_EQ(req.pid, pid);
resp.id = req.id;
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
close(listener);
}
/*
* Check that a pid in a sibling (i.e. unrelated) namespace shows up as 0, i.e.
* invalid.
*/
TEST(user_notification_sibling_pid_ns)
{
pid_t pid, pid2;
int status, listener;
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
ASSERT_EQ(prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0), 0) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
ASSERT_EQ(unshare(CLONE_NEWPID), 0);
pid2 = fork();
ASSERT_GE(pid2, 0);
if (pid2 == 0)
exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
exit(WEXITSTATUS(status));
}
/* Create the sibling ns, and sibling in it. */
ASSERT_EQ(unshare(CLONE_NEWPID), 0) {
if (errno == EPERM)
SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN");
}
ASSERT_EQ(errno, 0);
pid2 = fork();
ASSERT_GE(pid2, 0);
if (pid2 == 0) {
ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
/*
* The pid should be 0, i.e. the task is in some namespace that
* we can't "see".
*/
EXPECT_EQ(req.pid, 0);
resp.id = req.id;
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
exit(0);
}
close(listener);
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
EXPECT_EQ(waitpid(pid2, &status, 0), pid2);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
}
TEST(user_notification_fault_recv)
{
pid_t pid;
int status, listener;
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
ASSERT_EQ(unshare(CLONE_NEWUSER), 0) {
if (errno == EINVAL)
SKIP(return, "kernel missing CLONE_NEWUSER support");
}
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0)
exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
/* Do a bad recv() */
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, NULL), -1);
EXPECT_EQ(errno, EFAULT);
/* We should still be able to receive this notification, though. */
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
EXPECT_EQ(req.pid, pid);
resp.id = req.id;
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
}
TEST(seccomp_get_notif_sizes)
{
struct seccomp_notif_sizes sizes;
ASSERT_EQ(seccomp(SECCOMP_GET_NOTIF_SIZES, 0, &sizes), 0);
EXPECT_EQ(sizes.seccomp_notif, sizeof(struct seccomp_notif));
EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp));
}
TEST(user_notification_continue)
{
pid_t pid;
long ret;
int status, listener;
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
struct pollfd pollfd;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
int dup_fd, pipe_fds[2];
pid_t self;
ASSERT_GE(pipe(pipe_fds), 0);
dup_fd = dup(pipe_fds[0]);
ASSERT_GE(dup_fd, 0);
EXPECT_NE(pipe_fds[0], dup_fd);
self = getpid();
ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0);
exit(0);
}
pollfd.fd = listener;
pollfd.events = POLLIN | POLLOUT;
EXPECT_GT(poll(&pollfd, 1, -1), 0);
EXPECT_EQ(pollfd.revents, POLLIN);
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
pollfd.fd = listener;
pollfd.events = POLLIN | POLLOUT;
EXPECT_GT(poll(&pollfd, 1, -1), 0);
EXPECT_EQ(pollfd.revents, POLLOUT);
EXPECT_EQ(req.data.nr, __NR_dup);
resp.id = req.id;
resp.flags = SECCOMP_USER_NOTIF_FLAG_CONTINUE;
/*
* Verify that setting SECCOMP_USER_NOTIF_FLAG_CONTINUE enforces other
* args be set to 0.
*/
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
EXPECT_EQ(errno, EINVAL);
resp.error = USER_NOTIF_MAGIC;
resp.val = 0;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), -1);
EXPECT_EQ(errno, EINVAL);
resp.error = 0;
resp.val = 0;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) {
if (errno == EINVAL)
SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE");
}
skip:
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status)) {
if (WEXITSTATUS(status) == 2) {
SKIP(return, "Kernel does not support kcmp() syscall");
return;
}
}
}
TEST(user_notification_filter_empty)
{
pid_t pid;
long ret;
int status;
struct pollfd pollfd;
struct __clone_args args = {
.flags = CLONE_FILES,
.exit_signal = SIGCHLD,
};
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
pid = sys_clone3(&args, sizeof(args));
ASSERT_GE(pid, 0);
if (pid == 0) {
int listener;
listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER);
if (listener < 0)
_exit(EXIT_FAILURE);
if (dup2(listener, 200) != 200)
_exit(EXIT_FAILURE);
close(listener);
_exit(EXIT_SUCCESS);
}
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
/*
* The seccomp filter has become unused so we should be notified once
* the kernel gets around to cleaning up task struct.
*/
pollfd.fd = 200;
pollfd.events = POLLHUP;
EXPECT_GT(poll(&pollfd, 1, 2000), 0);
EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
}
static void *do_thread(void *data)
{
return NULL;
}
TEST(user_notification_filter_empty_threaded)
{
pid_t pid;
long ret;
int status;
struct pollfd pollfd;
struct __clone_args args = {
.flags = CLONE_FILES,
.exit_signal = SIGCHLD,
};
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
pid = sys_clone3(&args, sizeof(args));
ASSERT_GE(pid, 0);
if (pid == 0) {
pid_t pid1, pid2;
int listener, status;
pthread_t thread;
listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER);
if (listener < 0)
_exit(EXIT_FAILURE);
if (dup2(listener, 200) != 200)
_exit(EXIT_FAILURE);
close(listener);
pid1 = fork();
if (pid1 < 0)
_exit(EXIT_FAILURE);
if (pid1 == 0)
_exit(EXIT_SUCCESS);
pid2 = fork();
if (pid2 < 0)
_exit(EXIT_FAILURE);
if (pid2 == 0)
_exit(EXIT_SUCCESS);
if (pthread_create(&thread, NULL, do_thread, NULL) ||
pthread_join(thread, NULL))
_exit(EXIT_FAILURE);
if (pthread_create(&thread, NULL, do_thread, NULL) ||
pthread_join(thread, NULL))
_exit(EXIT_FAILURE);
if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) ||
WEXITSTATUS(status))
_exit(EXIT_FAILURE);
if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) ||
WEXITSTATUS(status))
_exit(EXIT_FAILURE);
exit(EXIT_SUCCESS);
}
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
/*
* The seccomp filter has become unused so we should be notified once
* the kernel gets around to cleaning up task struct.
*/
pollfd.fd = 200;
pollfd.events = POLLHUP;
EXPECT_GT(poll(&pollfd, 1, 2000), 0);
EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0);
}
TEST(user_notification_addfd)
{
pid_t pid;
long ret;
int status, listener, memfd, fd, nextfd;
struct seccomp_notif_addfd addfd = {};
struct seccomp_notif_addfd_small small = {};
struct seccomp_notif_addfd_big big = {};
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
/* 100 ms */
struct timespec delay = { .tv_nsec = 100000000 };
/* There may be arbitrary already-open fds at test start. */
memfd = memfd_create("test", 0);
ASSERT_GE(memfd, 0);
nextfd = memfd + 1;
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
/* fd: 4 */
/* Check that the basic notification machinery works */
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_EQ(listener, nextfd++);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
/* fds will be added and this value is expected */
if (syscall(__NR_getppid) != USER_NOTIF_MAGIC)
exit(1);
/* Atomic addfd+send is received here. Check it is a valid fd */
if (fcntl(syscall(__NR_getppid), F_GETFD) == -1)
exit(1);
exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
}
ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
addfd.srcfd = memfd;
addfd.newfd = 0;
addfd.id = req.id;
addfd.flags = 0x0;
/* Verify bad newfd_flags cannot be set */
addfd.newfd_flags = ~O_CLOEXEC;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
EXPECT_EQ(errno, EINVAL);
addfd.newfd_flags = O_CLOEXEC;
/* Verify bad flags cannot be set */
addfd.flags = 0xff;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
EXPECT_EQ(errno, EINVAL);
addfd.flags = 0;
/* Verify that remote_fd cannot be set without setting flags */
addfd.newfd = 1;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
EXPECT_EQ(errno, EINVAL);
addfd.newfd = 0;
/* Verify small size cannot be set */
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1);
EXPECT_EQ(errno, EINVAL);
/* Verify we can't send bits filled in unknown buffer area */
memset(&big, 0xAA, sizeof(big));
big.addfd = addfd;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1);
EXPECT_EQ(errno, E2BIG);
/* Verify we can set an arbitrary remote fd */
fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
EXPECT_EQ(fd, nextfd++);
EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
/* Verify we can set an arbitrary remote fd with large size */
memset(&big, 0x0, sizeof(big));
big.addfd = addfd;
fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big);
EXPECT_EQ(fd, nextfd++);
/* Verify we can set a specific remote fd */
addfd.newfd = 42;
addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
EXPECT_EQ(fd, 42);
EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
/* Resume syscall */
resp.id = req.id;
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
/*
* This sets the ID of the ADD FD to the last request plus 1. The
* notification ID increments 1 per notification.
*/
addfd.id = req.id + 1;
/* This spins until the underlying notification is generated */
while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
errno != -EINPROGRESS)
nanosleep(&delay, NULL);
memset(&req, 0, sizeof(req));
ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
ASSERT_EQ(addfd.id, req.id);
/* Verify we can do an atomic addfd and send */
addfd.newfd = 0;
addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd);
/*
* Child has earlier "low" fds and now 42, so we expect the next
* lowest available fd to be assigned here.
*/
EXPECT_EQ(fd, nextfd++);
ASSERT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
/*
* This sets the ID of the ADD FD to the last request plus 1. The
* notification ID increments 1 per notification.
*/
addfd.id = req.id + 1;
/* This spins until the underlying notification is generated */
while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 &&
errno != -EINPROGRESS)
nanosleep(&delay, NULL);
memset(&req, 0, sizeof(req));
ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
ASSERT_EQ(addfd.id, req.id);
resp.id = req.id;
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
/* Wait for child to finish. */
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
close(memfd);
}
TEST(user_notification_addfd_rlimit)
{
pid_t pid;
long ret;
int status, listener, memfd;
struct seccomp_notif_addfd addfd = {};
struct seccomp_notif req = {};
struct seccomp_notif_resp resp = {};
const struct rlimit lim = {
.rlim_cur = 0,
.rlim_max = 0,
};
memfd = memfd_create("test", 0);
ASSERT_GE(memfd, 0);
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
/* Check that the basic notification machinery works */
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0)
exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC);
ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0);
addfd.srcfd = memfd;
addfd.newfd_flags = O_CLOEXEC;
addfd.newfd = 0;
addfd.id = req.id;
addfd.flags = 0;
/* Should probably spot check /proc/sys/fs/file-nr */
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
EXPECT_EQ(errno, EMFILE);
addfd.flags = SECCOMP_ADDFD_FLAG_SEND;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
EXPECT_EQ(errno, EMFILE);
addfd.newfd = 100;
addfd.flags = SECCOMP_ADDFD_FLAG_SETFD;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1);
EXPECT_EQ(errno, EBADF);
resp.id = req.id;
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
/* Wait for child to finish. */
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
close(memfd);
}
/* Make sure PTRACE_O_SUSPEND_SECCOMP requires CAP_SYS_ADMIN. */
FIXTURE(O_SUSPEND_SECCOMP) {
pid_t pid;
};
FIXTURE_SETUP(O_SUSPEND_SECCOMP)
{
ERRNO_FILTER(block_read, E2BIG);
cap_value_t cap_list[] = { CAP_SYS_ADMIN };
cap_t caps;
self->pid = 0;
/* make sure we don't have CAP_SYS_ADMIN */
caps = cap_get_proc();
ASSERT_NE(NULL, caps);
ASSERT_EQ(0, cap_set_flag(caps, CAP_EFFECTIVE, 1, cap_list, CAP_CLEAR));
ASSERT_EQ(0, cap_set_proc(caps));
cap_free(caps);
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
ASSERT_EQ(0, prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_block_read));
self->pid = fork();
ASSERT_GE(self->pid, 0);
if (self->pid == 0) {
while (1)
pause();
_exit(127);
}
}
FIXTURE_TEARDOWN(O_SUSPEND_SECCOMP)
{
if (self->pid)
kill(self->pid, SIGKILL);
}
TEST_F(O_SUSPEND_SECCOMP, setoptions)
{
int wstatus;
ASSERT_EQ(0, ptrace(PTRACE_ATTACH, self->pid, NULL, 0));
ASSERT_EQ(self->pid, wait(&wstatus));
ASSERT_EQ(-1, ptrace(PTRACE_SETOPTIONS, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP));
if (errno == EINVAL)
SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)");
ASSERT_EQ(EPERM, errno);
}
TEST_F(O_SUSPEND_SECCOMP, seize)
{
int ret;
ret = ptrace(PTRACE_SEIZE, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP);
ASSERT_EQ(-1, ret);
if (errno == EINVAL)
SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)");
ASSERT_EQ(EPERM, errno);
}
/*
* get_nth - Get the nth, space separated entry in a file.
*
* Returns the length of the read field.
* Throws error if field is zero-lengthed.
*/
static ssize_t get_nth(struct __test_metadata *_metadata, const char *path,
const unsigned int position, char **entry)
{
char *line = NULL;
unsigned int i;
ssize_t nread;
size_t len = 0;
FILE *f;
f = fopen(path, "r");
ASSERT_NE(f, NULL) {
TH_LOG("Could not open %s: %s", path, strerror(errno));
}
for (i = 0; i < position; i++) {
nread = getdelim(&line, &len, ' ', f);
ASSERT_GE(nread, 0) {
TH_LOG("Failed to read %d entry in file %s", i, path);
}
}
fclose(f);
ASSERT_GT(nread, 0) {
TH_LOG("Entry in file %s had zero length", path);
}
*entry = line;
return nread - 1;
}
/* For a given PID, get the task state (D, R, etc...) */
static char get_proc_stat(struct __test_metadata *_metadata, pid_t pid)
{
char proc_path[100] = {0};
char status;
char *line;
snprintf(proc_path, sizeof(proc_path), "/proc/%d/stat", pid);
ASSERT_EQ(get_nth(_metadata, proc_path, 3, &line), 1);
status = *line;
free(line);
return status;
}
TEST(user_notification_fifo)
{
struct seccomp_notif_resp resp = {};
struct seccomp_notif req = {};
int i, status, listener;
pid_t pid, pids[3];
__u64 baseid;
long ret;
/* 100 ms */
struct timespec delay = { .tv_nsec = 100000000 };
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret) {
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
/* Setup a listener */
listener = user_notif_syscall(__NR_getppid,
SECCOMP_FILTER_FLAG_NEW_LISTENER);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
ret = syscall(__NR_getppid);
exit(ret != USER_NOTIF_MAGIC);
}
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
baseid = req.id + 1;
resp.id = req.id;
resp.error = 0;
resp.val = USER_NOTIF_MAGIC;
/* check that we make sure flags == 0 */
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
/* Start children, and generate notifications */
for (i = 0; i < ARRAY_SIZE(pids); i++) {
pid = fork();
if (pid == 0) {
ret = syscall(__NR_getppid);
exit(ret != USER_NOTIF_MAGIC);
}
pids[i] = pid;
}
/* This spins until all of the children are sleeping */
restart_wait:
for (i = 0; i < ARRAY_SIZE(pids); i++) {
if (get_proc_stat(_metadata, pids[i]) != 'S') {
nanosleep(&delay, NULL);
goto restart_wait;
}
}
/* Read the notifications in order (and respond) */
for (i = 0; i < ARRAY_SIZE(pids); i++) {
memset(&req, 0, sizeof(req));
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
EXPECT_EQ(req.id, baseid + i);
resp.id = req.id;
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
}
/* Make sure notifications were received */
for (i = 0; i < ARRAY_SIZE(pids); i++) {
EXPECT_EQ(waitpid(pids[i], &status, 0), pids[i]);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
}
}
/* get_proc_syscall - Get the syscall in progress for a given pid
*
* Returns the current syscall number for a given process
* Returns -1 if not in syscall (running or blocked)
*/
static long get_proc_syscall(struct __test_metadata *_metadata, int pid)
{
char proc_path[100] = {0};
long ret = -1;
ssize_t nread;
char *line;
snprintf(proc_path, sizeof(proc_path), "/proc/%d/syscall", pid);
nread = get_nth(_metadata, proc_path, 1, &line);
ASSERT_GT(nread, 0);
if (!strncmp("running", line, MIN(7, nread)))
ret = strtol(line, NULL, 16);
free(line);
return ret;
}
/* Ensure non-fatal signals prior to receive are unmodified */
TEST(user_notification_wait_killable_pre_notification)
{
struct sigaction new_action = {
.sa_handler = signal_handler,
};
int listener, status, sk_pair[2];
pid_t pid;
long ret;
char c;
/* 100 ms */
struct timespec delay = { .tv_nsec = 100000000 };
ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0);
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret)
{
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
listener = user_notif_syscall(
__NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
ASSERT_GE(listener, 0);
/*
* Check that we can kill the process with SIGUSR1 prior to receiving
* the notification. SIGUSR1 is wired up to a custom signal handler,
* and make sure it gets called.
*/
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
close(sk_pair[0]);
handled = sk_pair[1];
/* Setup the non-fatal sigaction without SA_RESTART */
if (sigaction(SIGUSR1, &new_action, NULL)) {
perror("sigaction");
exit(1);
}
ret = syscall(__NR_getppid);
/* Make sure we got a return from a signal interruption */
exit(ret != -1 || errno != EINTR);
}
/*
* Make sure we've gotten to the seccomp user notification wait
* from getppid prior to sending any signals
*/
while (get_proc_syscall(_metadata, pid) != __NR_getppid &&
get_proc_stat(_metadata, pid) != 'S')
nanosleep(&delay, NULL);
/* Send non-fatal kill signal */
EXPECT_EQ(kill(pid, SIGUSR1), 0);
/* wait for process to exit (exit checks for EINTR) */
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
}
/* Ensure non-fatal signals after receive are blocked */
TEST(user_notification_wait_killable)
{
struct sigaction new_action = {
.sa_handler = signal_handler,
};
struct seccomp_notif_resp resp = {};
struct seccomp_notif req = {};
int listener, status, sk_pair[2];
pid_t pid;
long ret;
char c;
/* 100 ms */
struct timespec delay = { .tv_nsec = 100000000 };
ASSERT_EQ(sigemptyset(&new_action.sa_mask), 0);
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret)
{
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0);
listener = user_notif_syscall(
__NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
close(sk_pair[0]);
handled = sk_pair[1];
/* Setup the sigaction without SA_RESTART */
if (sigaction(SIGUSR1, &new_action, NULL)) {
perror("sigaction");
exit(1);
}
/* Make sure that the syscall is completed (no EINTR) */
ret = syscall(__NR_getppid);
exit(ret != USER_NOTIF_MAGIC);
}
/*
* Get the notification, to make move the notifying process into a
* non-preemptible (TASK_KILLABLE) state.
*/
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
/* Send non-fatal kill signal */
EXPECT_EQ(kill(pid, SIGUSR1), 0);
/*
* Make sure the task enters moves to TASK_KILLABLE by waiting for
* D (Disk Sleep) state after receiving non-fatal signal.
*/
while (get_proc_stat(_metadata, pid) != 'D')
nanosleep(&delay, NULL);
resp.id = req.id;
resp.val = USER_NOTIF_MAGIC;
/* Make sure the notification is found and able to be replied to */
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0);
/*
* Make sure that the signal handler does get called once we're back in
* userspace.
*/
EXPECT_EQ(read(sk_pair[0], &c, 1), 1);
/* wait for process to exit (exit checks for USER_NOTIF_MAGIC) */
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFEXITED(status));
EXPECT_EQ(0, WEXITSTATUS(status));
}
/* Ensure fatal signals after receive are not blocked */
TEST(user_notification_wait_killable_fatal)
{
struct seccomp_notif req = {};
int listener, status;
pid_t pid;
long ret;
/* 100 ms */
struct timespec delay = { .tv_nsec = 100000000 };
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
ASSERT_EQ(0, ret)
{
TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!");
}
listener = user_notif_syscall(
__NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER |
SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV);
ASSERT_GE(listener, 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
/* This should never complete as it should get a SIGTERM */
syscall(__NR_getppid);
exit(1);
}
while (get_proc_stat(_metadata, pid) != 'S')
nanosleep(&delay, NULL);
/*
* Get the notification, to make move the notifying process into a
* non-preemptible (TASK_KILLABLE) state.
*/
EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0);
/* Kill the process with a fatal signal */
EXPECT_EQ(kill(pid, SIGTERM), 0);
/*
* Wait for the process to exit, and make sure the process terminated
* due to the SIGTERM signal.
*/
EXPECT_EQ(waitpid(pid, &status, 0), pid);
EXPECT_EQ(true, WIFSIGNALED(status));
EXPECT_EQ(SIGTERM, WTERMSIG(status));
}
/*
* TODO:
* - expand NNP testing
* - better arch-specific TRACE and TRAP handlers.
* - endianness checking when appropriate
* - 64-bit arg prodding
* - arch value testing (x86 modes especially)
* - verify that FILTER_FLAG_LOG filters generate log messages
* - verify that RET_LOG generates log messages
*/
TEST_HARNESS_MAIN