From 97a83aba3bc6376786984efde3e4a968fe553068 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rubens=20Brand=C3=A3o?= <git@rubens.io>
Date: Thu, 15 Feb 2024 12:13:46 -0300
Subject: [PATCH] feature(libqasan): add strndup (#1860)

* feature(libqasan): add asprintf and vasprintf

* feature(libqasan): add asprintf and vasprintf to hotpatch

* feature(libqasan): add strndup
---
 libafl_qemu/libqasan/hooks.c | 15 +++++++++++++++
 libafl_qemu/libqasan/patch.c |  1 +
 2 files changed, 16 insertions(+)

diff --git a/libafl_qemu/libqasan/hooks.c b/libafl_qemu/libqasan/hooks.c
index 8b27bb8094..c16b0a8250 100644
--- a/libafl_qemu/libqasan/hooks.c
+++ b/libafl_qemu/libqasan/hooks.c
@@ -471,6 +471,21 @@ char *strdup(const char *s) {
   return r;
 }
 
+char *strndup(const char *s, size_t n) {
+  void *rtv = __builtin_return_address(0);
+
+  QASAN_DEBUG("%14p: strndup(%p, %zu)\n", rtv, s, n);
+  size_t l = __libqasan_strnlen(s, n);
+  if (l > n) { l = n; }
+  QASAN_LOAD(s, l + 1);
+  void *r = __libqasan_malloc(l + 1);
+  __libqasan_memcpy(r, s, l);
+  ((char*)r)[l] = 0;
+  QASAN_DEBUG("\t\t = %p\n", r);
+
+  return r;
+}
+
 size_t strlen(const char *s) {
   void *rtv = __builtin_return_address(0);
 
diff --git a/libafl_qemu/libqasan/patch.c b/libafl_qemu/libqasan/patch.c
index 03c9ac2672..443c5a9b76 100644
--- a/libafl_qemu/libqasan/patch.c
+++ b/libafl_qemu/libqasan/patch.c
@@ -214,6 +214,7 @@ void __libqasan_hotpatch(void) {
   HOTPATCH(strncpy)
   HOTPATCH(stpcpy)
   HOTPATCH(strdup)
+  HOTPATCH(strndup)
   HOTPATCH(strlen)
   HOTPATCH(strnlen)
   HOTPATCH(strstr)