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wifi: mt76: mt7925: fix potential deadlock in mt7925_roc_abort_sync

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roc_abort_sync() can deadlock with roc_work(). roc_work() holds
dev->mt76.mutex, while cancel_work_sync() waits for roc_work()
to finish. If the caller already owns the same mutex, both
sides block and no progress is possible.

This deadlock can occur during station removal when
mt76_sta_state() -> mt76_sta_remove() ->
mt7925_mac_sta_remove_link() -> mt7925_mac_link_sta_remove() ->
mt7925_roc_abort_sync() invokes cancel_work_sync() while
roc_work() is still running and holding dev->mt76.mutex.

This avoids the mutex deadlock and preserves exactly-once
work ownership.

Fixes: 45064d19fd ("wifi: mt76: mt7925: fix a potential association failure upon resuming")
Co-developed-by: Quan Zhou <quan.zhou@mediatek.com>
Signed-off-by: Quan Zhou <quan.zhou@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Link: https://patch.msgid.link/20251216013849.17976-1-sean.wang@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Sean Wang 2025-12-15 19:38:49 -06:00 committed by Felix Fietkau
parent 8c7e19612b
commit dd08ca3f09
1 changed files with 9 additions and 5 deletions
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14
drivers/net/wireless/mediatek/mt76/mt7925/main.c
View File

@ -461,12 +461,16 @@ void mt7925_roc_abort_sync(struct mt792x_dev *dev)
{
struct mt792x_phy *phy = &dev->phy;
if (!test_and_clear_bit(MT76_STATE_ROC, &phy->mt76->state))
return;
timer_delete_sync(&phy->roc_timer);
cancel_work_sync(&phy->roc_work);
if (test_and_clear_bit(MT76_STATE_ROC, &phy->mt76->state))
ieee80211_iterate_interfaces(mt76_hw(dev),
IEEE80211_IFACE_ITER_RESUME_ALL,
mt7925_roc_iter, (void *)phy);
cancel_work(&phy->roc_work);
ieee80211_iterate_interfaces(mt76_hw(dev),
IEEE80211_IFACE_ITER_RESUME_ALL,
mt7925_roc_iter, (void *)phy);
}
EXPORT_SYMBOL_GPL(mt7925_roc_abort_sync);