[PATCH 3.11 130/208] iwlwifi: mvm: check sta_id/drain values in debugfs

[Luis Henriques]

3.11.10.2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johannes Berg <johannes.berg at intel.com>

commit 60765a47a433d54e4744c285ad127f182dcd80aa upstream.

The station ID must be valid, if it's out of range then
the array access may crash. Validate the station ID to
the array length, and also validate the drain value even
if that doesn't matter all that much.

Fixes: 8ca151b568b6 ("iwlwifi: add the MVM driver")
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/wireless/iwlwifi/mvm/debugfs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/iwlwifi/mvm/debugfs.c b/drivers/net/wireless/iwlwifi/mvm/debugfs.c
index c24a744..b52e8b6 100644
--- a/drivers/net/wireless/iwlwifi/mvm/debugfs.c
+++ b/drivers/net/wireless/iwlwifi/mvm/debugfs.c
@@ -119,6 +119,10 @@ static ssize_t iwl_dbgfs_sta_drain_write(struct file *file,
 
 	if (sscanf(buf, "%d %d", &sta_id, &drain) != 2)
 		return -EINVAL;
+	if (sta_id < 0 || sta_id >= IWL_MVM_STATION_COUNT)
+		return -EINVAL;
+	if (drain < 0 || drain > 1)
+		return -EINVAL;
 
 	mutex_lock(&mvm->mutex);
 
-- 
1.8.3.2