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 0A362C433F5 for ; Mon, 24 Jan 2022 19:33:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346923AbiAXTdp (ORCPT ); Mon, 24 Jan 2022 14:33:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352986AbiAXTbo (ORCPT ); Mon, 24 Jan 2022 14:31:44 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D6F0C0604C2; Mon, 24 Jan 2022 11:14:52 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 4C24FB8121A; Mon, 24 Jan 2022 19:14:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A36DC340E8; Mon, 24 Jan 2022 19:14:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643051690; bh=1WLUy3+wsMM5QE1xCX6fNDNOZgozuI55MqJAlY91xTs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XXrCw73JdvTOazH0VNzRu73rVUg8oNL5g4gu4eorldgrFDRWaZs4Csi2PposaeYJK BiLg2zNwHdEFLEwCOwgJaywUt8c0ECp9V+mRHM+EQrQzacj6ecSYwnv85ecZkvOP/p 44pId+QUOvjVJUEKW9Rv09KjAz00zHnhG8p3PaLY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hulk Robot , Wang Hai , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.19 055/239] media: dmxdev: fix UAF when dvb_register_device() fails Date: Mon, 24 Jan 2022 19:41:33 +0100 Message-Id: <20220124183944.881904471@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183943.102762895@linuxfoundation.org> References: <20220124183943.102762895@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wang Hai [ Upstream commit ab599eb11882f834951c436cc080c3455ba32b9b ] I got a use-after-free report: dvbdev: dvb_register_device: failed to create device dvb1.dvr0 (-12) ... ================================================================== BUG: KASAN: use-after-free in dvb_dmxdev_release+0xce/0x2f0 ... Call Trace: dump_stack_lvl+0x6c/0x8b print_address_description.constprop.0+0x48/0x70 kasan_report.cold+0x82/0xdb __asan_load4+0x6b/0x90 dvb_dmxdev_release+0xce/0x2f0 ... Allocated by task 7666: kasan_save_stack+0x23/0x50 __kasan_kmalloc+0x83/0xa0 kmem_cache_alloc_trace+0x22e/0x470 dvb_register_device+0x12f/0x980 dvb_dmxdev_init+0x1f3/0x230 ... Freed by task 7666: kasan_save_stack+0x23/0x50 kasan_set_track+0x20/0x30 kasan_set_free_info+0x24/0x40 __kasan_slab_free+0xf2/0x130 kfree+0xd1/0x5c0 dvb_register_device.cold+0x1ac/0x1fa dvb_dmxdev_init+0x1f3/0x230 ... When dvb_register_device() in dvb_dmxdev_init() fails, dvb_dmxdev_init() does not return a failure, and the memory pointed to by dvbdev or dvr_dvbdev is invalid at this point. If they are used subsequently, it will result in UFA or null-ptr-deref. If dvb_register_device() in dvb_dmxdev_init() fails, fix the bug by making dvb_dmxdev_init() return an error as well. Link: https://lore.kernel.org/linux-media/20211015085741.1203283-1-wanghai38@huawei.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Hulk Robot Signed-off-by: Wang Hai Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/dvb-core/dmxdev.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c index d548f98c7a67d..9e0ef3934fa3d 100644 --- a/drivers/media/dvb-core/dmxdev.c +++ b/drivers/media/dvb-core/dmxdev.c @@ -1412,7 +1412,7 @@ static const struct dvb_device dvbdev_dvr = { }; int dvb_dmxdev_init(struct dmxdev *dmxdev, struct dvb_adapter *dvb_adapter) { - int i; + int i, ret; if (dmxdev->demux->open(dmxdev->demux) < 0) return -EUSERS; @@ -1431,14 +1431,26 @@ int dvb_dmxdev_init(struct dmxdev *dmxdev, struct dvb_adapter *dvb_adapter) DMXDEV_STATE_FREE); } - dvb_register_device(dvb_adapter, &dmxdev->dvbdev, &dvbdev_demux, dmxdev, + ret = dvb_register_device(dvb_adapter, &dmxdev->dvbdev, &dvbdev_demux, dmxdev, DVB_DEVICE_DEMUX, dmxdev->filternum); - dvb_register_device(dvb_adapter, &dmxdev->dvr_dvbdev, &dvbdev_dvr, + if (ret < 0) + goto err_register_dvbdev; + + ret = dvb_register_device(dvb_adapter, &dmxdev->dvr_dvbdev, &dvbdev_dvr, dmxdev, DVB_DEVICE_DVR, dmxdev->filternum); + if (ret < 0) + goto err_register_dvr_dvbdev; dvb_ringbuffer_init(&dmxdev->dvr_buffer, NULL, 8192); return 0; + +err_register_dvr_dvbdev: + dvb_unregister_device(dmxdev->dvbdev); +err_register_dvbdev: + vfree(dmxdev->filter); + dmxdev->filter = NULL; + return ret; } EXPORT_SYMBOL(dvb_dmxdev_init); -- 2.34.1