From nobody Fri Feb 13 12:33:09 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7E05CE7A89 for ; Mon, 25 Sep 2023 09:18:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232963AbjIYJSK (ORCPT ); Mon, 25 Sep 2023 05:18:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230429AbjIYJSI (ORCPT ); Mon, 25 Sep 2023 05:18:08 -0400 Received: from zg8tmtyylji0my4xnjqumte4.icoremail.net (zg8tmtyylji0my4xnjqumte4.icoremail.net [162.243.164.118]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BD8609B; Mon, 25 Sep 2023 02:18:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=buaa.edu.cn; s=buaa; h=Received:From:To:Cc:Subject:Date: Message-Id:MIME-Version:Content-Transfer-Encoding; bh=REETuE6GPL qC+wOfMjtNk/ptknHVF6nEw+p3O+uBa4U=; b=PjIwLI76bsqDx1jJk3zTcnBqhg qMZ5BaoZ1ogBLOPlUPy31d1POoCRpiBWo1NZ/4wMnsKVjPB6iW87w4GnsKDjAeyJ l4xgiUEY30gf2T+D3mycri/VkH+oKvp5FjGzOqWWnCPdU8psnByFYQCwI6oMRaDM GNOtsLf+s9bnyVD3Q= Received: from oslab.. (unknown [10.130.159.144]) by coremail-app2 (Coremail) with SMTP id Nyz+CgDnq+E5UBFlidKuAA--.4843S4; Mon, 25 Sep 2023 17:17:47 +0800 (CST) From: Jia-Ju Bai To: hminas@synopsys.com, gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] usb: dwc2: fix possible NULL pointer dereference caused by driver concurrency Date: Mon, 25 Sep 2023 17:17:41 +0800 Message-Id: <20230925091741.797863-1-baijiaju@buaa.edu.cn> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: Nyz+CgDnq+E5UBFlidKuAA--.4843S4 X-Coremail-Antispam: 1UD129KBjvJXoW7Aw48XF4UZr4xtr43tF4fZrb_yoW8XF1xpa 1IqFyIyw4qvFsxtw45XFs5Wa17JwsxWryjkr4xtayrZws2v34xJ3WfGFySgrsYkrZ5AanI gF1DZw48CrWDta7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkE1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AE w4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2 IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2 z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcV Aq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j 6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64 vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxkIecxEwVCm-wCF04k20xvY0x0EwIxGrwCF 04k20xvE74AGY7Cv6cx26F1DJr1UJwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F4 0E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1l IxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxV AFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j 6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUdHU DUUUUU= X-CM-SenderInfo: yrruji46exttoohg3hdfq/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In _dwc2_hcd_urb_enqueue(), "urb->hcpriv =3D NULL" is executed without=20 holding the lock "hsotg->lock". In _dwc2_hcd_urb_dequeue(): spin_lock_irqsave(&hsotg->lock, flags); ... if (!urb->hcpriv) { dev_dbg(hsotg->dev, "## urb->hcpriv is NULL ##\n"); goto out; } rc =3D dwc2_hcd_urb_dequeue(hsotg, urb->hcpriv); // Use urb->hcpriv ... out: spin_unlock_irqrestore(&hsotg->lock, flags); When _dwc2_hcd_urb_enqueue() and _dwc2_hcd_urb_dequeue() are=20 concurrently executed, the NULL check of "urb->hcpriv" can be executed before "urb->hcpriv =3D NULL". After urb->hcpriv is NULL, it can be used=20 in the function call to dwc2_hcd_urb_dequeue(), which can cause a NULL=20 pointer dereference.=20 To fix this possible bug, "urb->hcpriv =3D NULL" should be executed with holding the lock "hsotg->lock". Signed-off-by: Jia-Ju Bai --- drivers/usb/dwc2/hcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index 657f1f659ffa..35c7a4df8e71 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -4769,8 +4769,8 @@ static int _dwc2_hcd_urb_enqueue(struct usb_hcd *hcd,= struct urb *urb, if (qh_allocated && qh->channel && qh->channel->qh =3D=3D qh) qh->channel->qh =3D NULL; fail2: - spin_unlock_irqrestore(&hsotg->lock, flags); urb->hcpriv =3D NULL; + spin_unlock_irqrestore(&hsotg->lock, flags); kfree(qtd); fail1: if (qh_allocated) { --=20 2.34.1