[patch] intel_scu_ipcutil: underflow in scu_reg_access()

From: Dan Carpenter
Date: Tue Jan 26 2016 - 04:25:35 EST


"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@xxxxxxxxxx>

diff --git a/drivers/platform/x86/intel_scu_ipcutil.c b/drivers/platform/x86/intel_scu_ipcutil.c
index 02bc5a6..aa45424 100644
--- 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;