From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74160C433E1 for ; Thu, 2 Jul 2020 01:29:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4750D20748 for ; Thu, 2 Jul 2020 01:29:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593653360; bh=vtSw3xO97ia0vKC4RxF9VceEbRCcZtdHfy9qfJCSPLk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JBlAlf//pNQRku456dVkaG+gzmId2zKqqr8U9n4xzwoF/yh633ITpvRU8gXQrqUVZ SPAujDHoMLmI+tTub3Z9eGu6qYBJLWIsq94wSUm9FoWzNaCc422bhu2HcTVOTatGTs AQKcPK+fffVRffngGeNonLfCooHBjJpZKecQ6E9k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728756AbgGBB3N (ORCPT ); Wed, 1 Jul 2020 21:29:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:59172 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729457AbgGBB1V (ORCPT ); Wed, 1 Jul 2020 21:27:21 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7299320874; Thu, 2 Jul 2020 01:27:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593653241; bh=vtSw3xO97ia0vKC4RxF9VceEbRCcZtdHfy9qfJCSPLk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kMa+duSV8XWjwolujRnTDpcBRrPBGd9iA1VoY56qNMV6W5Tq4emTNKzQNLGwq4bV7 DB1WdgL5uZg5aN9TeJbUxiuBwdLI7+EKg99WFkARJkUX+mmhOTwWE4O9MKbR34CgVm uxgWquNAvXDEC4t+IVqWWB4Y0C9WP6AMIOx+9fw8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tuomas Tynkkynen , syzbot+29dc7d4ae19b703ff947@syzkaller.appspotmail.com, "David S . Miller" , Sasha Levin , netdev@vger.kernel.org, linux-usb@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 07/13] usbnet: smsc95xx: Fix use-after-free after removal Date: Wed, 1 Jul 2020 21:27:06 -0400 Message-Id: <20200702012712.2701986-7-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200702012712.2701986-1-sashal@kernel.org> References: <20200702012712.2701986-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tuomas Tynkkynen [ Upstream commit b835a71ef64a61383c414d6bf2896d2c0161deca ] Syzbot reports an use-after-free in workqueue context: BUG: KASAN: use-after-free in mutex_unlock+0x19/0x40 kernel/locking/mutex.c:737 mutex_unlock+0x19/0x40 kernel/locking/mutex.c:737 __smsc95xx_mdio_read drivers/net/usb/smsc95xx.c:217 [inline] smsc95xx_mdio_read+0x583/0x870 drivers/net/usb/smsc95xx.c:278 check_carrier+0xd1/0x2e0 drivers/net/usb/smsc95xx.c:644 process_one_work+0x777/0xf90 kernel/workqueue.c:2274 worker_thread+0xa8f/0x1430 kernel/workqueue.c:2420 kthread+0x2df/0x300 kernel/kthread.c:255 It looks like that smsc95xx_unbind() is freeing the structures that are still in use by the concurrently running workqueue callback. Thus switch to using cancel_delayed_work_sync() to ensure the work callback really is no longer active. Reported-by: syzbot+29dc7d4ae19b703ff947@syzkaller.appspotmail.com Signed-off-by: Tuomas Tynkkynen Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/usb/smsc95xx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index e719ecd69d01b..6852ebafd4d3b 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -1327,7 +1327,7 @@ static void smsc95xx_unbind(struct usbnet *dev, struct usb_interface *intf) struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]); if (pdata) { - cancel_delayed_work(&pdata->carrier_check); + cancel_delayed_work_sync(&pdata->carrier_check); netif_dbg(dev, ifdown, dev->net, "free pdata\n"); kfree(pdata); pdata = NULL; -- 2.25.1