From 5e0ea3e3fca14587b4494f604c887761dc4f5a17 Mon Sep 17 00:00:00 2001
From: jvoisin
Date: Thu, 3 Aug 2023 19:41:27 +0200
Subject: Add hardening for memchr and memrchr

---
 include/string.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/include/string.h b/include/string.h
index 36f1df2..42a3aaf 100644
--- a/include/string.h
+++ b/include/string.h
@@ -30,6 +30,7 @@ extern "C" {
 #endif
 
 #undef memcpy
+#undef memchr
 #undef memmove
 #undef memset
 #undef strcat
@@ -80,6 +81,29 @@ _FORTIFY_FN(memset) void *memset(void * _FORTIFY_POS0 __d, int __c, size_t __n)
 	return __builtin_memset(__d, __c, __n);
 }
 
+__access(read_only, 1, 3)
+_FORTIFY_FN(memchr) void *memchr(const void * _FORTIFY_POS0 __d, int __c, size_t __n)
+{
+	size_t __b = __bos(__d, 0);
+
+	if (__n > __b)
+		__builtin_trap();
+	return __builtin_memchr(__d, __c, __n);
+}
+
+#if defined(_GNU_SOURCE)
+#undef memrchr
+__access(read_only, 1, 3)
+_FORTIFY_FN(memrchr) void *memrchr(const void * _FORTIFY_POS0 __d, int __c, size_t __n)
+{
+	size_t __b = __bos(__d, 0);
+
+	if (__n > __b)
+		__builtin_trap();
+	return __builtin_memrchr(__d, __c, __n);
+}
+#endif
+
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
  || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
  || defined(_BSD_SOURCE)
-- 
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