[PATCH 3.10 50/54] intel_scu_ipcutil: underflow in scu_reg_access()

Greg Kroah-Hartman
2016-02-24T03:56:14Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit b1d353ad3d5835b16724653b33c05124e1b5acf1 upstream.

"count" is controlled by the user and it can be negative. Let's prevent
that by making it unsigned. You have to have CAP_SYS_RAWIO to call this
function so the bug is not as serious as it could be.

Fixes: 5369c02d951a ('intel_scu_ipc: Utility driver for intel scu ipc')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/platform/x86/intel_scu_ipcutil.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/platform/x86/intel_scu_ipcutil.c
+++ b/drivers/platform/x86/intel_scu_ipcutil.c
@@ -49,7 +49,7 @@ struct scu_ipc_data {

static int scu_reg_access(u32 cmd, struct scu_ipc_data *data)
{
- int count = data->count;
+ unsigned int count = data->count;

if (count == 0 || count == 3 || count > 4)
return -EINVAL;