X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fenv%2F__stack_chk_fail.c;h=e53526020f751d34542f07c6b30d94c5dc08bf72;hb=c499c1084eaccd83e4b6e60883a5d92df0202c5e;hp=be0c184a635d5571471bef081a4f7d6f6e1e115d;hpb=55d061f031085f24d138664c897791aebe9a2fab;p=musl

diff --git a/src/env/__stack_chk_fail.c b/src/env/__stack_chk_fail.c
index be0c184a..e5352602 100644
--- a/src/env/__stack_chk_fail.c
+++ b/src/env/__stack_chk_fail.c
@@ -9,24 +9,23 @@ void __init_ssp(void *entropy)
 	if (entropy) memcpy(&__stack_chk_guard, entropy, sizeof(uintptr_t));
 	else __stack_chk_guard = (uintptr_t)&__stack_chk_guard * 1103515245;
 
-	__pthread_self()->CANARY = __stack_chk_guard;
-}
+#if UINTPTR_MAX >= 0xffffffffffffffff
+	/* Sacrifice 8 bits of entropy on 64bit to prevent leaking/
+	 * overwriting the canary via string-manipulation functions.
+	 * The NULL byte is on the second byte so that off-by-ones can
+	 * still be detected. Endianness is taken care of
+	 * automatically. */
+	((char *)&__stack_chk_guard)[1] = 0;
+#endif
 
-void __stack_chk_fail(void)
-{
-	a_crash();
+	__pthread_self()->canary = __stack_chk_guard;
 }
 
-#ifdef SHARED
-
-__attribute__((__visibility__("hidden")))
-void __stack_chk_fail_local(void)
+void __stack_chk_fail(void)
 {
 	a_crash();
 }
 
-#else
+hidden void __stack_chk_fail_local(void);
 
 weak_alias(__stack_chk_fail, __stack_chk_fail_local);
-
-#endif