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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E88FEC072A2 for ; Wed, 15 Nov 2023 19:49:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235378AbjKOTty (ORCPT ); Wed, 15 Nov 2023 14:49:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235376AbjKOTtx (ORCPT ); Wed, 15 Nov 2023 14:49:53 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7C60DC2 for ; Wed, 15 Nov 2023 11:49:50 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1D10C433C9; Wed, 15 Nov 2023 19:49:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700077790; bh=J2rlEtYN1xl5trT88SV7TwpdONuketFlladqDpBEmvg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aG+/uDDmstkMz1MLutjZpM2a0RpCey4mxji7tWOOe7LgV7O72Lv34cKJEA2cXM2WR rO0TcaGync/yWTsY+9JQc6z8pIZNqWVP57LzuvWAngMr37JvaoYdTjQy6HEk6Xf0EO JWntCytk0nEpyYeuvveioQv0QjyEszGmUXvY6V6M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zheng Wang , Hans Verkuil , Sasha Levin Subject: [PATCH 6.6 514/603] media: bttv: fix use after free error due to btv->timeout timer Date: Wed, 15 Nov 2023 14:17:39 -0500 Message-ID: <20231115191647.658348110@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191613.097702445@linuxfoundation.org> References: <20231115191613.097702445@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zheng Wang [ Upstream commit bd5b50b329e850d467e7bcc07b2b6bde3752fbda ] There may be some a race condition between timer function bttv_irq_timeout and bttv_remove. The timer is setup in probe and there is no timer_delete operation in remove function. When it hit kfree btv, the function might still be invoked, which will cause use after free bug. This bug is found by static analysis, it may be false positive. Fix it by adding del_timer_sync invoking to the remove function. cpu0 cpu1 bttv_probe ->timer_setup ->bttv_set_dma ->mod_timer; bttv_remove ->kfree(btv); ->bttv_irq_timeout ->USE btv Fixes: 162e6376ac58 ("media: pci: Convert timers to use timer_setup()") Signed-off-by: Zheng Wang Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/pci/bt8xx/bttv-driver.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c index aa708a0e5eac6..09a193bb87df3 100644 --- a/drivers/media/pci/bt8xx/bttv-driver.c +++ b/drivers/media/pci/bt8xx/bttv-driver.c @@ -3474,6 +3474,7 @@ static void bttv_remove(struct pci_dev *pci_dev) /* free resources */ free_irq(btv->c.pci->irq,btv); + del_timer_sync(&btv->timeout); iounmap(btv->bt848_mmio); release_mem_region(pci_resource_start(btv->c.pci,0), pci_resource_len(btv->c.pci,0)); -- 2.42.0