developer | 42b6328 | 2022-06-16 13:33:13 +0800 | [diff] [blame^] | 1 | From: Felix Fietkau <nbd@nbd.name> |
| 2 | Date: Sat, 26 Mar 2022 23:58:35 +0100 |
| 3 | Subject: [PATCH] mac80211: do not wake queues on a vif that is being stopped |
| 4 | |
| 5 | When a vif is being removed and sdata->bss is cleared, __ieee80211_wake_txqs |
| 6 | can still be called on it, which crashes as soon as sdata->bss is being |
| 7 | dereferenced. |
| 8 | To fix this properly, check for SDATA_STATE_RUNNING before waking queues, |
| 9 | and take the fq lock when setting it (to ensure that __ieee80211_wake_txqs |
| 10 | observes the change when running on a different CPU |
| 11 | |
| 12 | Signed-off-by: Felix Fietkau <nbd@nbd.name> |
| 13 | --- |
| 14 | |
| 15 | --- a/net/mac80211/iface.c |
| 16 | +++ b/net/mac80211/iface.c |
| 17 | @@ -377,7 +377,9 @@ static void ieee80211_do_stop(struct iee |
| 18 | bool cancel_scan; |
| 19 | struct cfg80211_nan_func *func; |
| 20 | |
| 21 | + spin_lock_bh(&local->fq.lock); |
| 22 | clear_bit(SDATA_STATE_RUNNING, &sdata->state); |
| 23 | + spin_unlock_bh(&local->fq.lock); |
| 24 | |
| 25 | cancel_scan = rcu_access_pointer(local->scan_sdata) == sdata; |
| 26 | if (cancel_scan) |
| 27 | --- a/net/mac80211/util.c |
| 28 | +++ b/net/mac80211/util.c |
| 29 | @@ -301,6 +301,9 @@ static void __ieee80211_wake_txqs(struct |
| 30 | local_bh_disable(); |
| 31 | spin_lock(&fq->lock); |
| 32 | |
| 33 | + if (!test_bit(SDATA_STATE_RUNNING, &sdata->state)) |
| 34 | + goto out; |
| 35 | + |
| 36 | if (sdata->vif.type == NL80211_IFTYPE_AP) |
| 37 | ps = &sdata->bss->ps; |
| 38 | |