[3.11.y.z extended stable] Patch "ARM: 7913/1: fix framepointer check in unwind_frame" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ARM: 7913/1: fix framepointer check in unwind_frame

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 21853e912ab13365098477fcd260b24059152512 Mon Sep 17 00:00:00 2001
From: Konstantin Khlebnikov <k.khlebnikov at samsung.com>
Date: Thu, 5 Dec 2013 14:23:48 +0100
Subject: ARM: 7913/1: fix framepointer check in unwind_frame

commit 3abb6671a9c04479c4bd026798a05f857393b7e2 upstream.

This patch fixes corner case when (fp + 4) overflows unsigned long,
for example: fp = 0xFFFFFFFF -> fp + 4 == 3.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov at samsung.com>
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/arm/kernel/stacktrace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index 00f79e5..af4e8c8 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -31,7 +31,7 @@ int notrace unwind_frame(struct stackframe *frame)
 	high = ALIGN(low, THREAD_SIZE);

 	/* check current frame pointer is within bounds */
-	if (fp < (low + 12) || fp + 4 >= high)
+	if (fp < low + 12 || fp > high - 4)
 		return -EINVAL;

 	/* restore the registers from the stack frame */
--
1.8.3.2