2011-04-29 14:48:18

by Dan Rosenberg

[permalink] [raw]
Subject: [PATCH] arm: prevent heap corruption in OABI semtimedop

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 <[email protected]>
Cc: [email protected]
---
arch/arm/kernel/sys_oabi-compat.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index 4ad8da1..af0aaeb 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)