linux-kernel - [PATCH v4 20/21] wifi: mt76: fix list corruption in mt76_wcid

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260116010519.37001-21-zac@zacbowling.com>
Date: Thu, 15 Jan 2026 17:05:18 -0800
From: Zac <zac@...bowling.com>
To: sean.wang@...nel.org
Cc: deren.wu@...iatek.com,
	kvalo@...nel.org,
	linux-kernel@...r.kernel.org,
	linux-mediatek@...ts.infradead.org,
	linux-wireless@...r.kernel.org,
	lorenzo@...nel.org,
	nbd@....name,
	linux@...me.work,
	ryder.lee@...iatek.com,
	sean.wang@...iatek.com,
	Zac <zac@...bowling.com>,
	Zac Bowling <zbowling@...il.com>
Subject: [PATCH v4 20/21] wifi: mt76: fix list corruption in mt76_wcid_cleanup

mt76_wcid_cleanup() was not removing wcid entries from sta_poll_list
before mt76_reset_device() reinitializes the master list. This leaves
stale pointers in wcid->poll_list, causing list corruption when
mt76_wcid_add_poll() later checks list_empty() and tries to add the
entry back.

The fix adds proper cleanup of poll_list in mt76_wcid_cleanup(),
matching how tx_list is already handled. This is similar to what
mt7996_mac_sta_deinit_link() already does correctly.

Fixes list corruption warnings like:
  list_add corruption. prev->next should be next (ffffffff...)

Signed-off-by: Zac Bowling <zbowling@...il.com>
---
 drivers/net/wireless/mediatek/mt76/mac80211.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c
index 75772979f4..d0c522909e 100644
--- a/drivers/net/wireless/mediatek/mt76/mac80211.c
+++ b/drivers/net/wireless/mediatek/mt76/mac80211.c
@@ -1716,6 +1716,16 @@ void mt76_wcid_cleanup(struct mt76_dev *dev, struct mt76_wcid *wcid)
 
 	idr_destroy(&wcid->pktid);
 
+	/* Remove from sta_poll_list to prevent list corruption after reset.
+	 * Without this, mt76_reset_device() reinitializes sta_poll_list but
+	 * leaves wcid->poll_list with stale pointers, causing list corruption
+	 * when mt76_wcid_add_poll() checks list_empty().
+	 */
+	spin_lock_bh(&dev->sta_poll_lock);
+	if (!list_empty(&wcid->poll_list))
+		list_del_init(&wcid->poll_list);
+	spin_unlock_bh(&dev->sta_poll_lock);
+
 	spin_lock_bh(&phy->tx_lock);
 
 	if (!list_empty(&wcid->tx_list))
-- 
2.52.0