ARM: 6891/1: 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.
Cc: stable@kernel.org
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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 @@
long err;
int i;
- if (nsops < 1)
+ if (nsops < 1 || nsops > SEMOPM)
return -EINVAL;
sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL);
if (!sops)