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 25A55168CB for ; Mon, 8 May 2023 11:36:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 069BEC433D2; Mon, 8 May 2023 11:36:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683545807; bh=zP4SmmFCklzsQNxOZOAd8ylAf+NZmF86OPhcupXYzNY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mGWFcW7PFeJ6WZXEwMcUPV0K35vQ2EbzPitN6biZFrdT3n27tJtZfMlXLzKd0863Z qYGTcQDOeBJ7dGWoaQGanYcIhHZQn2ZDuqMC6LeYg9nJ5TqF0h+7bbklR552IkZD2+ Ju0aBCcGBfeAqbG/L0Ny/aBFPbH/l4gxTbaxG+NU= 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 5.15 131/371] media: rkvdec: fix use after free bug in rkvdec_remove Date: Mon, 8 May 2023 11:45:32 +0200 Message-Id: <20230508094817.239657433@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094811.912279944@linuxfoundation.org> References: <20230508094811.912279944@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 4fd4a2907da70..bc4683a75e61f 100644 --- a/drivers/staging/media/rkvdec/rkvdec.c +++ b/drivers/staging/media/rkvdec/rkvdec.c @@ -1042,6 +1042,8 @@ 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