[PATCH] [27/98] ARM: 6891/1: prevent heap corruption in OABI semtimedop

Andi Kleen
2011-07-27T00:35:35Z

From: Dan Rosenberg <drosenberg@vsecurity.com>

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>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
arch/arm/kernel/sys_oabi-compat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.35.y/arch/arm/kernel/sys_oabi-compat.c
===================================================================
--- linux-2.6.35.y.orig/arch/arm/kernel/sys_oabi-compat.c
+++ linux-2.6.35.y/arch/arm/kernel/sys_oabi-compat.c
@@ -311,7 +311,7 @@ asmlinkage long sys_oabi_semtimedop(int
long err;
int i;

- if (nsops < 1)
+ if (nsops < 1 || nsops > SEMOPM)
return -EINVAL;
sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL);
if (!sops)