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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59267C433E2 for ; Sun, 30 Aug 2020 15:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2981E20720 for ; Sun, 30 Aug 2020 15:04:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OB5COtSU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726035AbgH3PEu (ORCPT ); Sun, 30 Aug 2020 11:04:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726030AbgH3PEt (ORCPT ); Sun, 30 Aug 2020 11:04:49 -0400 Received: from mail-oo1-xc41.google.com (mail-oo1-xc41.google.com [IPv6:2607:f8b0:4864:20::c41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04068C061573; Sun, 30 Aug 2020 08:04:49 -0700 (PDT) Received: by mail-oo1-xc41.google.com with SMTP id k13so523583oor.2; Sun, 30 Aug 2020 08:04:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id; bh=BuCpEw+EZ23rQm56+0nKrPRHRJlGh2aurjyoqcnesH8=; b=OB5COtSUNnP5PJ4wdVP/6+MrypbDCHdoNk54WOKjOPRe/jAHZqhBbTLdyqE5+G4dOz cxDb/yKwEOlG873h7CtUAkUOWV9nzABG5nAwCVRoouk8+fjlXe2vuP74P/7S8wBXHFmY mf1qakKt1kLlqfWIL5jVZcwA3AXheyfX8EQmwCWOu7ImiXR46tywdmWTuR3BSSVxluNd BvTzP3+4yFZDbd1mkscO2ZEc8J4oVtLHl4wChY0mEgjsTSNItqFKATdRs1D2feWtdXbA Yd6jjbtlbeTMV1sQCpJY5KDSR1bivwG9G/ZZLA+PQhc34iket8l5wPtb6vB2/ojAe0F4 PZaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id; bh=BuCpEw+EZ23rQm56+0nKrPRHRJlGh2aurjyoqcnesH8=; b=ktxgReDOdoU6p/k19N8sAJyXFR1wOrW1QeQuZjvF7vvE6fqcgNP2abrBH2rcKwPAPB hrDi89zmxpJ5k01y/nAAFTDX984MoyKfiOEpK325tjD2XHgSVbLVWa11r5ExxjyRTdwh 9dM23FNZQxAvpOH8e+RNQSvIRipSnvgSkSQ1AimboRcIWa1u3qknxvVcyeh9SKZ5NrP9 lbBAKAvD5fmyxQblB7pmZEwdDCUjyot566vQ3HduBxmiSExEOcise8GLrjtwT+9tQdm5 jZXQji9G6TcPrjm8QFlcVVDrHpd8+SZOOwYL7s1q0yNE62aR1sgXxzMNQUhmzXvE0MFR xdkQ== X-Gm-Message-State: AOAM532B0oPdkG/gyGFnXE/Po8uaIsnyXJFWfpksI5ljRk9j7MuuOsbW 5xy5eRKpTFcSAf7PgEw4QMw= X-Google-Smtp-Source: ABdhPJyjV//48S9aVDUGtC9l8bZgiGM0RCaQxnsJ2nXVgCgjgQFTsA5rGb7yXz5svqlsJhhpYWHtdQ== X-Received: by 2002:a4a:e98e:: with SMTP id s14mr5092375ood.28.1598799887541; Sun, 30 Aug 2020 08:04:47 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id y7sm661387oih.55.2020.08.30.08.04.45 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sun, 30 Aug 2020 08:04:46 -0700 (PDT) From: Guenter Roeck To: Laurent Pinchart Cc: Mauro Carvalho Chehab , Sakari Ailus , linux-uvc-devel@lists.sourceforge.net, linux-usb@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Guenter Roeck Subject: [PATCH 0/5] media: uvcvideo: Fix race conditions Date: Sun, 30 Aug 2020 08:04:38 -0700 Message-Id: <20200830150443.167286-1-linux@roeck-us.net> X-Mailer: git-send-email 2.17.1 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org The uvcvideo code has no lock protection against USB disconnects while video operations are ongoing. This has resulted in random error reports, typically pointing to a crash in usb_ifnum_to_if(), called from usb_hcd_alloc_bandwidth(). A typical traceback is as follows. usb 1-4: USB disconnect, device number 3 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 5633 Comm: V4L2CaptureThre Not tainted 4.19.113-08536-g5d29ca36db06 #1 Hardware name: GOOGLE Edgar, BIOS Google_Edgar.7287.167.156 03/25/2019 RIP: 0010:usb_ifnum_to_if+0x29/0x40 Code: <...> RSP: 0018:ffffa46f42a47a80 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff904a396c9000 RDX: ffff904a39641320 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffa46f42a47a80 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000009975 R11: 0000000000000009 R12: 0000000000000000 R13: ffff904a396b3800 R14: ffff904a39e88000 R15: 0000000000000000 FS: 00007f396448e700(0000) GS:ffff904a3ba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000016cb46000 CR4: 00000000001006f0 Call Trace: usb_hcd_alloc_bandwidth+0x1ee/0x30f usb_set_interface+0x1a3/0x2b7 uvc_video_start_transfer+0x29b/0x4b8 [uvcvideo] uvc_video_start_streaming+0x91/0xdd [uvcvideo] uvc_start_streaming+0x28/0x5d [uvcvideo] vb2_start_streaming+0x61/0x143 [videobuf2_common] vb2_core_streamon+0xf7/0x10f [videobuf2_common] uvc_queue_streamon+0x2e/0x41 [uvcvideo] uvc_ioctl_streamon+0x42/0x5c [uvcvideo] __video_do_ioctl+0x33d/0x42a video_usercopy+0x34e/0x5ff ? video_ioctl2+0x16/0x16 v4l2_ioctl+0x46/0x53 do_vfs_ioctl+0x50a/0x76f ksys_ioctl+0x58/0x83 __x64_sys_ioctl+0x1a/0x1e do_syscall_64+0x54/0xde While this is problem rarely observed in the field, it is relatively easy to reproduce by adding msleep() calls into the code. I don't presume to claim that I found every issue, but this patch series should fix at least the major problems. The patch series was tested exensively on a Chromebook running chromeos-4.19 and on a Linux system running a v5.8.y based kernel. ---------------------------------------------------------------- Guenter Roeck (5): media: uvcvideo: Cancel async worker earlier media: uvcvideo: Lock video streams and queues while unregistering media: uvcvideo: Release stream queue when unregistering video device media: uvcvideo: Protect uvc queue file operations against disconnect media: uvcvideo: In uvc_v4l2_open, check if video device is registered drivers/media/usb/uvc/uvc_ctrl.c | 11 ++++++---- drivers/media/usb/uvc/uvc_driver.c | 12 ++++++++++ drivers/media/usb/uvc/uvc_queue.c | 32 +++++++++++++++++++++++++-- drivers/media/usb/uvc/uvc_v4l2.c | 45 ++++++++++++++++++++++++++++++++++++-- drivers/media/usb/uvc/uvcvideo.h | 1 + 5 files changed, 93 insertions(+), 8 deletions(-)