34 lines
763 B
C
34 lines
763 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include <errno.h>
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#include <linux/capability.h>
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struct kernel_cap_struct {
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__u32 cap[_LINUX_CAPABILITY_U32S_3];
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} __attribute__((preserve_access_index));
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struct cred {
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struct kernel_cap_struct cap_effective;
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} __attribute__((preserve_access_index));
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char _license[] SEC("license") = "GPL";
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SEC("lsm.s/userns_create")
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int BPF_PROG(test_userns_create, const struct cred *cred, int ret)
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{
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struct kernel_cap_struct caps = cred->cap_effective;
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int cap_index = CAP_TO_INDEX(CAP_SYS_ADMIN);
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__u32 cap_mask = CAP_TO_MASK(CAP_SYS_ADMIN);
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if (ret)
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return 0;
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ret = -EPERM;
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if (caps.cap[cap_index] & cap_mask)
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return 0;
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return -EPERM;
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}
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