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 3920BDF53 for ; Mon, 15 May 2023 16:39:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D885C433EF; Mon, 15 May 2023 16:39:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684168776; bh=N5hqo7c0icuJv8vUBc6mUJchXYaP8Dzkb0wFJ5KCdZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=puPFuLAq6lqZhjd2uALrrN0kMf8R/z7o0GwGVx7hYjSYwp4StlTzBr8Q8PjYqmL73 rbpPySXTpANsOe+6Z4KA26uHr6f1R7lHJzXv9DnOXGm9FyXpT9htuj7+mUP4hw2NIB 949IV5cBqE6zXoqipzSIxwxlwUVUS++rL7Vf4qM8= 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 4.19 038/191] media: dm1105: Fix use after free bug in dm1105_remove due to race condition Date: Mon, 15 May 2023 18:24:35 +0200 Message-Id: <20230515161708.563213990@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230515161707.203549282@linuxfoundation.org> References: <20230515161707.203549282@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 5abda7a16698d4d1f47af1168d8fa2c640116b4a ] In dm1105_probe, it called dm1105_ir_init and bound &dm1105->ir.work with dm1105_emit_key. When it handles IRQ request with dm1105_irq, it may call schedule_work to start the work. When we call dm1105_remove to remove the driver, there may be a sequence as follows: Fix it by finishing the work before cleanup in dm1105_remove CPU0 CPU1 |dm1105_emit_key dm1105_remove | dm1105_ir_exit | rc_unregister_device | rc_free_device | rc_dev_release | kfree(dev); | | | rc_keydown | //use Fixes: 34d2f9bf189c ("V4L/DVB: dm1105: use dm1105_dev & dev instead of dm1105dvb") Signed-off-by: Zheng Wang Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/pci/dm1105/dm1105.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/pci/dm1105/dm1105.c b/drivers/media/pci/dm1105/dm1105.c index 1ddb0576fb7b1..dc3fc69e44806 100644 --- a/drivers/media/pci/dm1105/dm1105.c +++ b/drivers/media/pci/dm1105/dm1105.c @@ -1188,6 +1188,7 @@ static void dm1105_remove(struct pci_dev *pdev) struct dvb_demux *dvbdemux = &dev->demux; struct dmx_demux *dmx = &dvbdemux->dmx; + cancel_work_sync(&dev->ir.work); dm1105_ir_exit(dev); dmx->close(dmx); dvb_net_release(&dev->dvbnet); -- 2.39.2