mac80211: Properly WARN on HW scan before restart

The following race was possible:

1. The device driver requests HW restart.
2. A scan is requested from user space and is propagated
   to the driver. During this flow HW_SCANNING flag is set.
3. The thread that handles the HW restart is scheduled,
   and before starting the actual reconfiguration it
   checks that HW_SCANNING is not set. The flow does so
   without acquiring any lock, and thus the WARN fires.

Fix this by checking that HW_SCANNING is on only after RTNL is
acquired, i.e., user space scan request handling is no longer
in transit.

Signed-off-by: Ilan Peer <[email protected]>
Signed-off-by: Luca Coelho <[email protected]>
Link: https://lore.kernel.org/r/iwlwifi.20210618133832.8238ab3e19ab.I2693c581c70251472b4f9089e37e06fb2c18268f@changeid
Signed-off-by: Johannes Berg <[email protected]>

0 files changed, 0 insertions, 0 deletions