From nobody Fri Sep 25 17:46:10 2026 Received: from zg8tndyumtaxlji0oc4xnzya.icoremail.net (zg8tndyumtaxlji0oc4xnzya.icoremail.net [46.101.248.176]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 669362E542C; Thu, 10 Sep 2026 02:10:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.101.248.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789006214; cv=none; b=t2Jmst1bjCRx5p1+jPuOPbL8lnrZGFTNlklPTJAg8lSObpbGLYz3QrMCMCPL4h/Dpk7Dzh7ze8l6rbcXTGLC25LQfFPIpT0vNJ1bQaUgHTBSRwIjcqG3DZQ8/ko/Nut2U4BuwYPHhEdVWv2KzAtmshbxP4TPG/OqsajaIBJvyiE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789006214; c=relaxed/simple; bh=6X4PBf5BZXBmLYQRCarw6LEMDqC8sbd/96iuOUcMbsU=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=WstKZj5JqBHnC1GhgpjtfGxfcCpGbR6FwfB0Lb/NDiVra/yZol1R/cyzawzbpZ+ztnCPHHDjYRteovX7KdLRY8snsZwBWODGlnt5eAbZaujAXFOfDmBECtmOPO2SqEzc8WDcCMPt3hqIIpIf5DBJuM/PnShU2JhR5CPQezFb1xc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn; spf=pass smtp.mailfrom=zju.edu.cn; arc=none smtp.client-ip=46.101.248.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zju.edu.cn Received: from zju.edu.cn (unknown [10.98.66.117]) by mtasvr (Coremail) with SMTP id _____wCHcH56EaJqKg8FAQ--.1192S3; Thu, 10 Sep 2026 10:10:02 +0800 (CST) Received: from localhost.localdomain (unknown [10.98.66.117]) by mail-app4 (Coremail) with SMTP id zi_KCgCn2TB6EaJqaQ+rAw--.47397S2; Thu, 10 Sep 2026 10:10:02 +0800 (CST) From: Fan Wu To: Loic Poulain , wcn36xx@lists.infradead.org Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Fan Wu , Song Li Subject: [PATCH] wifi: wcn36xx: Fix potential use-after-free in TX ack timer teardown Date: Thu, 10 Sep 2026 02:09:07 +0000 Message-Id: <20260910020907.3353-1-fanwu01@zju.edu.cn> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: zi_KCgCn2TB6EaJqaQ+rAw--.47397S2 X-CM-SenderInfo: qrstjiaswqq6lmxovvfxof0/ X-CM-DELIVERINFO: =?B?1kkibQXKKxbFmtjJiESix3B1w3vZ3A9ovKVTomAyoQazvoRs/NHSP8GI2EvgeEEW7R sfnXz+g1OQfMo27QHy5TwQyZyt9d8Xr08ZnRfj2RxFhaKwHmhjm7l4LO8xHhS7sy8/3QVB t0d+DN4Erlu6FYofXtHN5RPxYw6l01w8CbPzC/8w X-Coremail-Antispam: 1Uk129KBj93XoW7CF15GFyfJr43Jr4xAFyDCFX_yoW8ArW7pr Z7Wr4I9FykZFs7JwsrWr48WFy8Jan5ArZF9Fyxua13ZFn5CFn5tFy5uF9xZFWUtayqqFy2 yr45tr15G3ZxA3cCm3ZEXasCq-sJn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUU9Gb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AK xVW0oVCq3wAac4AC62xK8xCEY4vEwIxC4wAS0I0E0xvYzxvE52x082IY62kv0487Mc804V CY07AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AK xVWUXVWUAwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48Icx kI7VAKI48JM4x0Y48IcxkI7VAKI48G6xCjnVAKz4kxMxAIw28IcxkI7VAKI48JMxC20s02 6xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_Jr I_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v2 6r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj4 0_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8 JrUvcSsGvfC2KfnxnUUI43ZEXa7IU8I_M3UUUUU== Content-Type: text/plain; charset="utf-8" wcn36xx_dxe_deinit() tears down the TX ack timer with timer_delete(), which only dequeues the timer and does not wait for a callback that is already executing; the preceding free_irq() calls synchronize the interrupt handlers only. The callback, wcn36xx_dxe_tx_timer(), can therefore be running past the teardown and use the wcn freed along with the ieee80211_hw in wcn36xx_remove(): it takes wcn->dxe_lock, reads wcn->tx_ack_skb and passes wcn->hw to ieee80211_tx_status_irqsafe(). Fix this by using timer_shutdown_sync(), which waits for a running callback and also prevents the timer from being rearmed again. The timer is set up again by wcn36xx_dxe_init() on the next start, so the start/stop cycle is unaffected. This issue was found by an in-house static analysis tool. Fixes: fdf21cc37149 ("wcn36xx: Add TX ack support") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.6 Co-developed-by: Song Li Signed-off-by: Song Li Signed-off-by: Fan Wu Reviewed-by: Loic Poulain --- drivers/net/wireless/ath/wcn36xx/dxe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/wcn36xx/dxe.c b/drivers/net/wireless/= ath/wcn36xx/dxe.c index 44020ec26..801f1218e 100644 --- a/drivers/net/wireless/ath/wcn36xx/dxe.c +++ b/drivers/net/wireless/ath/wcn36xx/dxe.c @@ -1055,7 +1055,7 @@ void wcn36xx_dxe_deinit(struct wcn36xx *wcn) =20 free_irq(wcn->tx_irq, wcn); free_irq(wcn->rx_irq, wcn); - timer_delete(&wcn->tx_ack_timer); + timer_shutdown_sync(&wcn->tx_ack_timer); =20 if (wcn->tx_ack_skb) { ieee80211_tx_status_irqsafe(wcn->hw, wcn->tx_ack_skb);