From patchwork Thu Jul 15 18:37:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 478336 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 8B9B4C636CB for ; Thu, 15 Jul 2021 18:41:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C78A613D0 for ; Thu, 15 Jul 2021 18:41:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229940AbhGOSn5 (ORCPT ); Thu, 15 Jul 2021 14:43:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:43882 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229574AbhGOSn5 (ORCPT ); Thu, 15 Jul 2021 14:43:57 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 53F6D613CA; Thu, 15 Jul 2021 18:41:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626374462; bh=D0aqLcDHnyIhmX9cVux80w3kOxWK9bN3LSxoqo//I1U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fdqvSTMUH9Lk2tKVNfjQYVMVDp8j8t/qVsyCX28bfe+iUqAp4fhV6x9wknvn2FZgk MKyh0A2y6EDbiPrhIZU3oYcyiuQi4fP/GVSvjVchN87lNG6TR6aqaOLMM8i2XtftAl hcvVRtWiNjkE4ImFD7t2zxwn7MIoMTKoKihSZIqA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hulk Robot , Zou Wei , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 010/122] atm: nicstar: Fix possible use-after-free in nicstar_cleanup() Date: Thu, 15 Jul 2021 20:37:37 +0200 Message-Id: <20210715182450.976392699@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210715182448.393443551@linuxfoundation.org> References: <20210715182448.393443551@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zou Wei [ Upstream commit 34e7434ba4e97f4b85c1423a59b2922ba7dff2ea ] This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself. Reported-by: Hulk Robot Signed-off-by: Zou Wei Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/atm/nicstar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/atm/nicstar.c b/drivers/atm/nicstar.c index bb9835c62641..5ec7b6a60145 100644 --- a/drivers/atm/nicstar.c +++ b/drivers/atm/nicstar.c @@ -297,7 +297,7 @@ static void __exit nicstar_cleanup(void) { XPRINTK("nicstar: nicstar_cleanup() called.\n"); - del_timer(&ns_timer); + del_timer_sync(&ns_timer); pci_unregister_driver(&nicstar_driver);