From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 82F63433C9 for ; Wed, 15 Nov 2023 19:36:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hu0RL/TP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31C0BC433C8; Wed, 15 Nov 2023 19:36:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700076963; bh=e0seoj7LTsnn1L6AY6pD90UrieCXGqQDd8Ra2LUyiUU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hu0RL/TPD99OtUAHE8Ax1O+6kYB/QeO248RZ+Xfnr4Z6q/INYp76iZ/Q1oJGI5xKI ykW840A0E53s6IAyHB+L1OFIBS5yPCy9k1O2P+vlRFhLy8+gXu1SCQPEupXLn0yLvR VSsZtfASe9Ug/fun7LF/8SgbuYRY/P45VPXwC32U= 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 6.5 477/550] media: bttv: fix use after free error due to btv->timeout timer Date: Wed, 15 Nov 2023 14:17:41 -0500 Message-ID: <20231115191633.933186961@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191600.708733204@linuxfoundation.org> References: <20231115191600.708733204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-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 734f02b91aa31..a50cae25b5463 100644 --- a/drivers/media/pci/bt8xx/bttv-driver.c +++ b/drivers/media/pci/bt8xx/bttv-driver.c @@ -3830,6 +3830,7 @@ 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