From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA9762E3AFF; Tue, 15 Jul 2025 13:27:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752586057; cv=none; b=PLjqf8cQqSXF1BdmHgdII4bTV/bYixY8xmDZkp7X8LFXqZU8ZQQ2i2Xn0dLIfy1iYU2TScPeSghSae0Sjm3WWRV2AvvCkcJ1oF365crpmBAbo8Z8aipg103HomMg9vFVCRSxNZNcc7WxUdXlhZDVFAbn7g8T9sKSOnItF5EP6i4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752586057; c=relaxed/simple; bh=3WchZIK0yDR6Li5PBrbQuvKq1FogV0ZdyUOIULy8pEI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bgXV/RZ/ueetmAmEIwBT+UWrCAHiV9Epd2nfpc9FTqwVx1zIkuqF87GYr3jqN/5aUq4Y/tyLFwP63ARWfy6daQdJqg70Cfj1UQ6TsPhNkO5+deLvAxEs1/4B5M86kat2NYn4EeFbJEYN7aNRnHu0QlrR7NZ6xGbxfAxnaoBQ6wQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LcitySYq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LcitySYq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E4FAC4CEE3; Tue, 15 Jul 2025 13:27:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1752586057; bh=3WchZIK0yDR6Li5PBrbQuvKq1FogV0ZdyUOIULy8pEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LcitySYq6W8kpwU1N7Az7/kBXIJ7PNbeXNbLb1ii3I4sdHBnG3EZKDRlK2J2+DdGn WEJhbf9e/HIy+ge0wpOEO6lrceXM9GzPib+MH15acrxEkvf7Ez9BJpQTurILF4Bcaa d3qP4uSJMy0zFTam9KSBkAjOq4rfWz4IZK7Zecxs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daniil Dulov , Johannes Berg , Sasha Levin Subject: [PATCH 6.6 078/109] wifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev() Date: Tue, 15 Jul 2025 15:13:34 +0200 Message-ID: <20250715130802.005419827@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250715130758.864940641@linuxfoundation.org> References: <20250715130758.864940641@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniil Dulov [ 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 --- 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 5d534e15a844f..278875c02f41f 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; -- 2.39.5