| From: Felix Fietkau <nbd@nbd.name> |
| Date: Sat, 26 Mar 2022 23:58:35 +0100 |
| Subject: [PATCH] mac80211: do not wake queues on a vif that is being stopped |
| |
| When a vif is being removed and sdata->bss is cleared, __ieee80211_wake_txqs |
| can still be called on it, which crashes as soon as sdata->bss is being |
| dereferenced. |
| To fix this properly, check for SDATA_STATE_RUNNING before waking queues, |
| and take the fq lock when setting it (to ensure that __ieee80211_wake_txqs |
| observes the change when running on a different CPU |
| |
| Signed-off-by: Felix Fietkau <nbd@nbd.name> |
| --- |
| |
| --- a/net/mac80211/iface.c |
| +++ b/net/mac80211/iface.c |
| @@ -377,7 +377,9 @@ static void ieee80211_do_stop(struct iee |
| 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); |
| |
| cancel_scan = rcu_access_pointer(local->scan_sdata) == sdata; |
| if (cancel_scan) |
| --- a/net/mac80211/util.c |
| +++ b/net/mac80211/util.c |
| @@ -301,6 +301,9 @@ static void __ieee80211_wake_txqs(struct |
| local_bh_disable(); |
| spin_lock(&fq->lock); |
| |
| + if (!test_bit(SDATA_STATE_RUNNING, &sdata->state)) |
| + goto out; |
| + |
| if (sdata->vif.type == NL80211_IFTYPE_AP) |
| ps = &sdata->bss->ps; |
| |