From patchwork Mon Oct 14 07:41:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ricardo Ribalda Delgado X-Patchwork-Id: 3034581 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8D950BF924 for ; Mon, 14 Oct 2013 07:41:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 32DE920253 for ; Mon, 14 Oct 2013 07:41:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B8BB20237 for ; Mon, 14 Oct 2013 07:41:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752316Ab3JNHlh (ORCPT ); Mon, 14 Oct 2013 03:41:37 -0400 Received: from mail-la0-f50.google.com ([209.85.215.50]:58228 "EHLO mail-la0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750778Ab3JNHlg (ORCPT ); Mon, 14 Oct 2013 03:41:36 -0400 Received: by mail-la0-f50.google.com with SMTP id gx14so5244003lab.23 for ; Mon, 14 Oct 2013 00:41:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=llHxFty2Z5PCxoKvssCWG1QZhHbqMBaOmtK6/RZvTyo=; b=HWN3NUzt3i2OsWzJ58YQscuxZAkrwjN42NBzFOie6AcsVz7Kmncd4oQvPSgqkzNCLz ODBNewWCXXuSQzbIp3EuTE8WpZsP5s6o96q3xsQx90wBsJFJiPnSmKYMrzn55pEzm/R5 JO/TrlmBOvdrAnEQ0uKFenhoy7roiilgkReY1hcBk+b6mP2J/aRpS8Q4r8MTnAp1MrCk CUozLff3m2e3ufEUyFWl+Vi2rjMW0WW/sRIdb+tQq5ec+yIBV2ZvmNLX5DAPSoi8Z57N WlMZMp+GjKIgKpOR1c+4iIY3WWG/e2r6Y0ZJI+A2tqZ1Dc/yAg3BhOGYfMHyXBT7y1n1 1ZHA== X-Received: by 10.152.44.225 with SMTP id h1mr30033578lam.15.1381736494775; Mon, 14 Oct 2013 00:41:34 -0700 (PDT) Received: from neopili.qtec.com (0x4dd4aed9.adsl.cybercity.dk. [77.212.174.217]) by mx.google.com with ESMTPSA id ua4sm42881345lbb.17.1969.12.31.16.00.00 (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 14 Oct 2013 00:41:33 -0700 (PDT) From: Ricardo Ribalda Delgado To: Pawel Osciak , Marek Szyprowski , Kyungmin Park , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ricardo Ribalda Delgado Subject: [PATCH] videobuf2: Add missing lock held on vb2_fop_relase Date: Mon, 14 Oct 2013 09:41:29 +0200 Message-Id: <1381736489-27852-1-git-send-email-ricardo.ribalda@gmail.com> X-Mailer: git-send-email 1.8.4.rc3 In-Reply-To: References: Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP vb2_fop_relase does not held the lock although it is modifying the queue->owner field. This could lead to race conditions on the vb2_perform_io function when multiple applications are accessing the video device via read/write API: [ 308.297741] BUG: unable to handle kernel NULL pointer dereference at 0000000000000260 [ 308.297759] IP: [] vb2_perform_fileio+0x372/0x610 [videobuf2_core] [ 308.297794] PGD 159719067 PUD 158119067 PMD 0 [ 308.297812] Oops: 0000 #1 SMP [ 308.297826] Modules linked in: qt5023_video videobuf2_dma_sg qtec_xform videobuf2_vmalloc videobuf2_memops videobuf2_core qtec_white qtec_mem gpio_xilinx qtec_cmosis qtec_pcie fglrx(PO) spi_xilinx spi_bitbang qt5023 [ 308.297888] CPU: 1 PID: 2189 Comm: java Tainted: P O 3.11.0-qtec-standard #1 [ 308.297919] Hardware name: QTechnology QT5022/QT5022, BIOS PM_2.1.0.309 X64 05/23/2013 [ 308.297952] task: ffff8801564e1690 ti: ffff88014dc02000 task.ti: ffff88014dc02000 [ 308.297962] RIP: 0010:[] [] vb2_perform_fileio+0x372/0x610 [videobuf2_core] [ 308.297985] RSP: 0018:ffff88014dc03df8 EFLAGS: 00010202 [ 308.297995] RAX: 0000000000000000 RBX: ffff880158a23000 RCX: dead000000100100 [ 308.298003] RDX: 0000000000000000 RSI: dead000000200200 RDI: 0000000000000000 [ 308.298012] RBP: ffff88014dc03e58 R08: 0000000000000000 R09: 0000000000000001 [ 308.298020] R10: ffffea00051e8380 R11: ffff88014dc03fd8 R12: ffff880158a23070 [ 308.298029] R13: ffff8801549040b8 R14: 0000000000198000 R15: 0000000001887e60 [ 308.298040] FS: 00007f65130d5700(0000) GS:ffff88015ed00000(0000) knlGS:0000000000000000 [ 308.298049] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 308.298057] CR2: 0000000000000260 CR3: 0000000159630000 CR4: 00000000000007e0 [ 308.298064] Stack: [ 308.298071] ffff880156416c00 0000000000198000 0000000000000000 ffff880100000001 [ 308.298087] ffff88014dc03f50 00000000810a79ca 0002000000000001 ffff880154904718 [ 308.298101] ffff880156416c00 0000000000198000 ffff880154904338 ffff88014dc03f50 [ 308.298116] Call Trace: [ 308.298143] [] vb2_read+0x14/0x20 [videobuf2_core] [ 308.298198] [] vb2_fop_read+0xc4/0x120 [videobuf2_core] [ 308.298252] [] v4l2_read+0x7e/0xc0 [ 308.298296] [] vfs_read+0xa9/0x160 [ 308.298312] [] SyS_read+0x52/0xb0 [ 308.298328] [] tracesys+0xd0/0xd5 [ 308.298335] Code: e5 d6 ff ff 83 3d be 24 00 00 04 89 c2 4c 8b 45 b0 44 8b 4d b8 0f 8f 20 02 00 00 85 d2 75 32 83 83 78 03 00 00 01 4b 8b 44 c5 48 <8b> 88 60 02 00 00 85 c9 0f 84 b0 00 00 00 8b 40 58 89 c2 41 89 [ 308.298487] RIP [] vb2_perform_fileio+0x372/0x610 [videobuf2_core] [ 308.298507] RSP [ 308.298514] CR2: 0000000000000260 [ 308.298526] ---[ end trace e8f01717c96d1e41 ]--- Signed-off-by: Ricardo Ribalda Delgado Acked-by: Hans Verkuil Acked-by: Marek Szyprowski --- drivers/media/v4l2-core/videobuf2-core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 9fc4bab..3a961ee 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -2588,8 +2588,15 @@ int vb2_fop_release(struct file *file) struct video_device *vdev = video_devdata(file); if (file->private_data == vdev->queue->owner) { + struct mutex *lock; + + lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; + if (lock) + mutex_lock(lock); vb2_queue_release(vdev->queue); vdev->queue->owner = NULL; + if (lock) + mutex_unlock(lock); } return v4l2_fh_release(file); }