6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Felix Fietkau [ Upstream commit 2fb6480c52f611338e1b0abe5e6219be1fc9ab75 ] When mt76_wcid_alloc() fails, mt7915_add_interface() returned without clearing the vif_mask/omac_mask bits it had already set, without removing the firmware dev info added earlier, and without clearing a monitor_vif pointer to the vif mac80211 is about to free. mac80211 does not call remove_interface() for a failed add, so the indices and firmware dev entry leaked permanently and testmode could dereference the stale monitor_vif. Add a proper error unwind. Fixes: b619e01380ee ("mt76: fix MBSS index condition in DBDC mode") Link: https://patch.msgid.link/20260724124813.3961474-4-nbd@nbd.name Signed-off-by: Felix Fietkau Signed-off-by: Sasha Levin --- drivers/net/wireless/mediatek/mt76/mt7915/main.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/main.c b/drivers/net/wireless/mediatek/mt76/mt7915/main.c index 05d22da7ee654..864f636666e58 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7915/main.c +++ b/drivers/net/wireless/mediatek/mt76/mt7915/main.c @@ -248,7 +248,7 @@ static int mt7915_add_interface(struct ieee80211_hw *hw, idx = mt76_wcid_alloc(dev->mt76.wcid_mask, mt7915_wtbl_size(dev)); if (idx < 0) { ret = -ENOSPC; - goto out; + goto err; } INIT_LIST_HEAD(&mvif->sta.rc_list); @@ -279,7 +279,17 @@ static int mt7915_add_interface(struct ieee80211_hw *hw, mt7915_mcu_add_sta(dev, vif, NULL, true); rcu_assign_pointer(dev->mt76.wcid[idx], &mvif->sta.wcid); + mutex_unlock(&dev->mt76.mutex); + + return 0; + +err: + dev->mt76.vif_mask &= ~BIT_ULL(mvif->mt76.idx); + phy->omac_mask &= ~BIT_ULL(mvif->mt76.omac_idx); + mt7915_mcu_add_dev_info(phy, vif, false); out: + if (phy->monitor_vif == vif) + phy->monitor_vif = NULL; mutex_unlock(&dev->mt76.mutex); return ret; -- 2.53.0