From f30b9af6d6be6692144e322ecacbb5421195ce78 Mon Sep 17 00:00:00 2001 From: Daniil Dulov Date: Fri, 26 Sep 2025 17:23:06 +0800 Subject: [PATCH] wifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev() stable inclusion from stable-v6.6.99 commit 5420de65efbeb6503bcf1d43451c9df67ad60298 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICTB3J CVE: CVE-2025-38513 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5420de65efbeb6503bcf1d43451c9df67ad60298 -------------------------------- [ Upstream commit 74b1ec9f5d627d2bdd5e5b6f3f81c23317657023 ] There is a potential NULL pointer dereference in zd_mac_tx_to_dev(). For example, the following is possible: T0 T1 zd_mac_tx_to_dev() /* len == skb_queue_len(q) */ while (len > ZD_MAC_MAX_ACK_WAITERS) { filter_ack() spin_lock_irqsave(&q->lock, flags); /* position == skb_queue_len(q) */ for (i=1; itype == NL80211_IFTYPE_AP) skb = __skb_dequeue(q); spin_unlock_irqrestore(&q->lock, flags); skb_dequeue() -> NULL Since there is a small gap between checking skb queue length and skb being unconditionally dequeued in zd_mac_tx_to_dev(), skb_dequeue() can return NULL. Then the pointer is passed to zd_mac_tx_status() where it is dereferenced. In order to avoid potential NULL pointer dereference due to situations like above, check if skb is not NULL before passing it to zd_mac_tx_status(). Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 459c51ad6e1f ("zd1211rw: port to mac80211") Signed-off-by: Daniil Dulov Link: https://patch.msgid.link/20250626114619.172631-1-d.dulov@aladdin.ru Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin Signed-off-by: likunyu15 --- drivers/net/wireless/zydas/zd1211rw/zd_mac.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/zydas/zd1211rw/zd_mac.c b/drivers/net/wireless/zydas/zd1211rw/zd_mac.c index 5d534e15a844..278875c02f41 100644 --- a/drivers/net/wireless/zydas/zd1211rw/zd_mac.c +++ b/drivers/net/wireless/zydas/zd1211rw/zd_mac.c @@ -583,7 +583,11 @@ void zd_mac_tx_to_dev(struct sk_buff *skb, int error) skb_queue_tail(q, skb); while (skb_queue_len(q) > ZD_MAC_MAX_ACK_WAITERS) { - zd_mac_tx_status(hw, skb_dequeue(q), + skb = skb_dequeue(q); + if (!skb) + break; + + zd_mac_tx_status(hw, skb, mac->ack_pending ? mac->ack_signal : 0, NULL); mac->ack_pending = 0; -- Gitee