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 49785C072A2 for ; Wed, 15 Nov 2023 22:04:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344379AbjKOWEH (ORCPT ); Wed, 15 Nov 2023 17:04:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344381AbjKOWEG (ORCPT ); Wed, 15 Nov 2023 17:04:06 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52A6318B for ; Wed, 15 Nov 2023 14:04:03 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDFF5C433CB; Wed, 15 Nov 2023 22:04:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700085842; bh=4yIAk2HBnPvWsxL33qJQjBelZxrzK2XWNOD+tFQwND8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HDMSreNVamSxeYH4txBw9Rkm5AmlmWO++BeirvutPGbdF7i5JJLZmeCpgUtpF0nB3 qHyd4YDHVooqxpqEKYUpIxEJM+1hFQwRPIweFN8qy+83wXGtZf60IGYxogFec43NER JHwhq/3ok4eHI/2ckCIKGlc7tGmqCnm5uZ5NUIoY= 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 5.4 091/119] media: bttv: fix use after free error due to btv->timeout timer Date: Wed, 15 Nov 2023 17:01:21 -0500 Message-ID: <20231115220135.458602894@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115220132.607437515@linuxfoundation.org> References: <20231115220132.607437515@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 5.4-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 6441e7d63d971..a0be1ca89b29a 100644 --- a/drivers/media/pci/bt8xx/bttv-driver.c +++ b/drivers/media/pci/bt8xx/bttv-driver.c @@ -4258,6 +4258,7 @@ 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