diff options
| author | Ilan Peer <ilan.peer@intel.com> | 2021-06-18 13:41:37 +0300 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2021-06-23 11:29:14 +0200 |
| commit | 45daaa1318410794de956fb8e9d06aed2dbb23d0 (patch) | |
| tree | fc22b2a47304fdd7e0577d5b7f4a59de6a3c356f | |
| parent | dd3e4fc75b4ab8186a133cfe9d49666a2f8186e0 (diff) | |
| download | linux-45daaa1318410794de956fb8e9d06aed2dbb23d0.tar.bz2 | |
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 <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210618133832.8238ab3e19ab.I2693c581c70251472b4f9089e37e06fb2c18268f@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
| -rw-r--r-- | net/mac80211/main.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 822ff388410e..cde142fa8cb3 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -257,14 +257,13 @@ static void ieee80211_restart_work(struct work_struct *work) /* wait for scan work complete */ flush_workqueue(local->workqueue); flush_work(&local->sched_scan_stopped_work); + flush_work(&local->radar_detected_work); + + rtnl_lock(); WARN(test_bit(SCAN_HW_SCANNING, &local->scanning), "%s called with hardware scan in progress\n", __func__); - flush_work(&local->radar_detected_work); - /* we might do interface manipulations, so need both */ - rtnl_lock(); - wiphy_lock(local->hw.wiphy); list_for_each_entry(sdata, &local->interfaces, list) { /* * XXX: there may be more work for other vif types and even |