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 977D1320A for ; Mon, 8 May 2023 11:09:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16A50C433EF; Mon, 8 May 2023 11:09:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683544151; bh=Xy+BvZGyEipNBxUZR0L1092kcoflM3Nty4IXV4AJ8HA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H91cxAI8A3Rqzg7u9pz8Pmj34fdBaVYP9V9ZsL4Iv7svbxgDVIHUyQDOnna9V28Ae OSy+lW7Wi+F84o2ienS4tImhb2ojELyHt0GiPJINpQsQinPbsFq3HKWVRKGx8c1i5V hIRC8j06j5suwf4cVkXPQA4NI6ON6fw89fCdUYA8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zheng Wang , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 6.3 286/694] media: rkvdec: fix use after free bug in rkvdec_remove Date: Mon, 8 May 2023 11:42:01 +0200 Message-Id: <20230508094441.579022833@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094432.603705160@linuxfoundation.org> References: <20230508094432.603705160@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Zheng Wang [ Upstream commit 3228cec23b8b29215e18090c6ba635840190993d ] In rkvdec_probe, rkvdec->watchdog_work is bound with rkvdec_watchdog_func. Then rkvdec_vp9_run may be called to start the work. If we remove the module which will call rkvdec_remove to make cleanup, there may be a unfinished work. The possible sequence is as follows, which will cause a typical UAF bug. Fix it by canceling the work before cleanup in rkvdec_remove. CPU0 CPU1 |rkvdec_watchdog_func rkvdec_remove | rkvdec_v4l2_cleanup| v4l2_m2m_release | kfree(m2m_dev); | | | v4l2_m2m_get_curr_priv | m2m_dev->curr_ctx //use Fixes: cd33c830448b ("media: rkvdec: Add the rkvdec driver") Signed-off-by: Zheng Wang Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/staging/media/rkvdec/rkvdec.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c index 7bab7586918c1..82806f198074a 100644 --- a/drivers/staging/media/rkvdec/rkvdec.c +++ b/drivers/staging/media/rkvdec/rkvdec.c @@ -1066,6 +1066,8 @@ static int rkvdec_remove(struct platform_device *pdev) { struct rkvdec_dev *rkvdec = platform_get_drvdata(pdev); + cancel_delayed_work_sync(&rkvdec->watchdog_work); + rkvdec_v4l2_cleanup(rkvdec); pm_runtime_disable(&pdev->dev); pm_runtime_dont_use_autosuspend(&pdev->dev); -- 2.39.2