From: Arjan van de Ven <arjan@linux.intel.com>
Date: Tue, 26 Sep 2006 08:52:39 +0000 (+0200)
Subject: [PATCH] Add the __stack_chk_fail() function
X-Git-Tag: v2.6.19-rc1~1077^2~48
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3162f751d04086a9d006342de63ac8f44fe0f72a;p=linux-2.6

[PATCH] Add the __stack_chk_fail() function

GCC emits a call to a __stack_chk_fail() function when the stack canary is
not matching the expected value.

Since this is a bad security issue; lets panic the kernel rather than limping
along; the kernel really can't be trusted anymore when this happens.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>
---

diff --git a/kernel/panic.c b/kernel/panic.c
index d2db3e2209..6ceb664fb5 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -271,3 +271,15 @@ void oops_exit(void)
 {
 	do_oops_enter_exit();
 }
+
+#ifdef CONFIG_CC_STACKPROTECTOR
+/*
+ * Called when gcc's -fstack-protector feature is used, and
+ * gcc detects corruption of the on-stack canary value
+ */
+void __stack_chk_fail(void)
+{
+	panic("stack-protector: Kernel stack is corrupted");
+}
+EXPORT_SYMBOL(__stack_chk_fail);
+#endif