From: Dan Rosenberg <drosenberg@vsecurity.com>
Date: Fri, 29 Apr 2011 14:48:07 +0000 (+0100)
Subject: ARM: 6891/1: prevent heap corruption in OABI semtimedop
X-Git-Tag: v2.6.38.6~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=36f96751ce09f4ab400e93408cc602d2e080a799;p=thirdparty%2Fkernel%2Fstable.git

ARM: 6891/1: prevent heap corruption in OABI semtimedop

commit 0f22072ab50cac7983f9660d33974b45184da4f9 upstream.

When CONFIG_OABI_COMPAT is set, the wrapper for semtimedop does not
bound the nsops argument.  A sufficiently large value will cause an
integer overflow in allocation size, followed by copying too much data
into the allocated buffer.  Fix this by restricting nsops to SEMOPM.
Untested.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index 4ad8da15ef2b3..af0aaebf4de62 100644
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c
@@ -311,7 +311,7 @@ asmlinkage long sys_oabi_semtimedop(int semid,
 	long err;
 	int i;
 
-	if (nsops < 1)
+	if (nsops < 1 || nsops > SEMOPM)
 		return -EINVAL;
 	sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL);
 	if (!sops)