tree 6f645a02217b84c7b2a16147708a300985109f22
parent 959eb2fd70df86a089e9e31be654462235952a24
author Johannes Berg <johannes.berg@intel.com> 1449008126 +0100
committer Johannes Berg <johannes.berg@intel.com> 1449236612 +0100

mac80211: reject zero cookie in mgmt-tx/roc cancel

When cancelling, you can cancel "any" (first in list) mgmt-tx
or remain-on-channel operation by using the value 0 for the
cookie along with the *opposite* operation, i.e.
 * cancel the first mgmt-tx by cancelling roc with 0 cookie
 * cancel the first roc by cancelling mgmt-tx with 0 cookie

This isn't really that bad since userspace should only pass
cookies that we gave it, but could lead to hard-to-debug
issues so better prevent it and reject zero values since we
never hand those out.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>