diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2022-07-17 21:21:52 +0900 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-07-26 13:23:05 -0700 |
| commit | aa40d5a43526cca9439a2b45fcfdcd016594dece (patch) | |
| tree | 57ec3310310ba0880c04e5b3fddade8da4a2a6a6 | |
| parent | 9b134b1694ec8926926ba6b7b80884ea829245a0 (diff) | |
| download | lwn-aa40d5a43526cca9439a2b45fcfdcd016594dece.tar.gz lwn-aa40d5a43526cca9439a2b45fcfdcd016594dece.zip | |
wifi: mac80211: do not abuse fq.lock in ieee80211_do_stop()
lockdep complains use of uninitialized spinlock at ieee80211_do_stop() [1],
for commit f856373e2f31ffd3 ("wifi: mac80211: do not wake queues on a vif
that is being stopped") guards clear_bit() using fq.lock even before
fq_init() from ieee80211_txq_setup_flows() initializes this spinlock.
According to discussion [2], Toke was not happy with expanding usage of
fq.lock. Since __ieee80211_wake_txqs() is called under RCU read lock, we
can instead use synchronize_rcu() for flushing ieee80211_wake_txqs().
Link: https://syzkaller.appspot.com/bug?extid=eceab52db7c4b961e9d6 [1]
Link: https://lkml.kernel.org/r/874k0zowh2.fsf@toke.dk [2]
Reported-by: syzbot <syzbot+eceab52db7c4b961e9d6@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: f856373e2f31ffd3 ("wifi: mac80211: do not wake queues on a vif that is being stopped")
Tested-by: syzbot <syzbot+eceab52db7c4b961e9d6@syzkaller.appspotmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@kernel.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/9cc9b81d-75a3-3925-b612-9d0ad3cab82b@I-love.SAKURA.ne.jp
[ pick up commit 3598cb6e1862 ("wifi: mac80211: do not abuse fq.lock in ieee80211_do_stop()") from -next]
Link: https://lore.kernel.org/all/87o7xcq6qt.fsf@kernel.org/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/mac80211/iface.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 15a73b7fdd75..1a9ada411879 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -377,9 +377,8 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do bool cancel_scan; struct cfg80211_nan_func *func; - spin_lock_bh(&local->fq.lock); clear_bit(SDATA_STATE_RUNNING, &sdata->state); - spin_unlock_bh(&local->fq.lock); + synchronize_rcu(); /* flush _ieee80211_wake_txqs() */ cancel_scan = rcu_access_pointer(local->scan_sdata) == sdata; if (cancel_scan) |