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 E172BC072A2 for ; Wed, 15 Nov 2023 21:07:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235586AbjKOVHg (ORCPT ); Wed, 15 Nov 2023 16:07:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235605AbjKOVH0 (ORCPT ); Wed, 15 Nov 2023 16:07:26 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1FAA6D7A for ; Wed, 15 Nov 2023 13:07:23 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24EB1C4E75D; Wed, 15 Nov 2023 20:51:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700081517; bh=beA4sBBNTJlFGdGAN1d+yRgE8j4aGzvPJ03/o58U65Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=diURzp36IKUJvkozammry3h1ur9tWr1aZbZeONHle/LV9r10+F4nYC2H2X6aG1KRC tydGQvKd1LmoYxPiwmiPx3pQOL3TfEMe2K+hcN3ZdWRyGR5mPGcsHoHH7cAsqV2jy9 oadgDSQt/W9NQm6rDT0Fptj+0XG4XAZYojkMTNr8= 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 5.15 202/244] media: bttv: fix use after free error due to btv->timeout timer Date: Wed, 15 Nov 2023 15:36:34 -0500 Message-ID: <20231115203600.474140307@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115203548.387164783@linuxfoundation.org> References: <20231115203548.387164783@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 5.15-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 661ebfa7bf3f5..c4bf7b7109ce4 100644 --- a/drivers/media/pci/bt8xx/bttv-driver.c +++ b/drivers/media/pci/bt8xx/bttv-driver.c @@ -4250,6 +4250,7 @@ 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