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=-0.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 34B70C2BC61 for ; Mon, 29 Oct 2018 09:40:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF65B2084A for ; Mon, 29 Oct 2018 09:40:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AF65B2084A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729648AbeJ2S14 (ORCPT ); Mon, 29 Oct 2018 14:27:56 -0400 Received: from mail-it1-f200.google.com ([209.85.166.200]:53505 "EHLO mail-it1-f200.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729594AbeJ2S14 (ORCPT ); Mon, 29 Oct 2018 14:27:56 -0400 Received: by mail-it1-f200.google.com with SMTP id f79-v6so8937804ita.3 for ; Mon, 29 Oct 2018 02:40:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=8FT4cEW7VV4LHx2UPHr5/Cr6dAbs0BeFYMDeAiAND6w=; b=iwQpkEI3Rplm9m9HJH//ZcGEIUvyfNa2ffbrfhIT8jrHMdwJ4TE9aa4h3y+WcqlqAz EEn5qmn9fBDj4XfTbczQfb/ExY7+Vz40yNHJJgYWz8oSjQ1qn8iXqIzPSt7aH4e3FMNf Rk0RheSk/gNQX/G2oQ65eX9peC4dN5Swrpfn9QJbAx0FQ9Gr/o/i/hQB4yJDErkTamIK tf7Zpls5gh3nDe/bAy6OstM/QrNJy92goYq2Lk+0o5gpElM3NASdbpegcgbrGubACYZZ JyxV8vWifjangjBaDEUtNOMUrZcqIib5JIUC4CcjZR2zIKHE2N+hVTFV16pLE8gyu3QP O0+Q== X-Gm-Message-State: AGRZ1gKNPMl19BVbTg7iUY4ZUh8N+ehm4RToX/qytB3G2JmElOApr2Il kV/Hm/a9jyByc3FxSlxQNruAFIxQhDAHsd/BC06qfg534u7a X-Google-Smtp-Source: AJdET5cIRhGYmWRj27QRooa8Yg1iQyBQOnkfGpJxzFWBXmxDAO1j22/o9POdqE1IDUx1N5OI7/rZBJf9D2bgsKwvtblDWTPjIZop MIME-Version: 1.0 X-Received: by 2002:a24:c3:: with SMTP id 186-v6mr8277600ita.39.1540806003408; Mon, 29 Oct 2018 02:40:03 -0700 (PDT) Date: Mon, 29 Oct 2018 02:40:03 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000080601805795ada2e@google.com> Subject: INFO: task hung in vivid_stop_generating_vid_cap From: syzbot To: hverkuil@xs4all.nl, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 8c60c36d0b8c Add linux-next specific files for 20181019 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1608ccf5400000 kernel config: https://syzkaller.appspot.com/x/.config?x=ddc97ab84fb1ff2a dashboard link: https://syzkaller.appspot.com/bug?extid=06283a66a648cd073885 compiler: gcc (GCC) 8.0.1 20180413 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+06283a66a648cd073885@syzkaller.appspotmail.com VMExit: intr_info=00000000 errcode=00000000 ilen=00000003 reason=80000021 qualification=0000000000000003 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xfffffe6382838c64 EPT pointer = 0x00000001c4f5101e INFO: task syz-executor4:791 blocked for more than 140 seconds. Not tainted 4.19.0-rc8-next-20181019+ #99 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D23272 791 5784 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480 schedule+0xfe/0x460 kernel/sched/core.c:3524 schedule_timeout+0x1cc/0x260 kernel/time/timer.c:1780 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x427/0x8a0 kernel/sched/completion.c:136 kthread_stop+0x1a4/0x8f0 kernel/kthread.c:550 vivid_stop_generating_vid_cap+0x2bc/0x93b drivers/media/platform/vivid/vivid-kthread-cap.c:919 vid_cap_stop_streaming+0x8d/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:259 __vb2_queue_cancel+0x171/0xca0 drivers/media/common/videobuf2/videobuf2-core.c:1668 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1804 __vb2_cleanup_fileio+0x73/0x160 drivers/media/common/videobuf2/videobuf2-core.c:2325 vb2_core_queue_release+0x1e/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2052 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:672 [inline] _vb2_fop_release+0x1d2/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:843 vb2_fop_release+0x77/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:857 vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474 v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x3bc/0xa70 fs/file_table.c:279 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411021 Code: 4c 89 f6 48 89 c7 48 89 ca 48 89 4c 24 10 4c 89 54 24 08 e8 b1 a3 ff ff 48 8b 4c 24 10 41 c6 04 0f 00 4c 8b 7c 24 28 4c 8b 54 <24> 08 45 0f b6 37 e9 db fc ff ff 0f 1f 40 00 41 80 f8 29 74 7f ba RSP: 002b:00007ffebf8f0810 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000411021 RDX: 0000001b2ca20000 RSI: 0000000000730430 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000030c04255 R09: 0000000030c04259 R10: 00007ffebf8f0740 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000447 R15: 0000000000000004 Showing all locks held in the system: 1 lock held by khungtaskd/1008: #0: 00000000b994d395 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5554: #0: 0000000064483821 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5644: #0: 0000000088b7a22a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003463365c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5645: #0: 00000000b07a05bf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000accbc122 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5646: #0: 000000003b71eb89 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e3b18d3f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5647: #0: 00000000c8f2c425 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000646fd3b6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5648: #0: 000000004a4ae0cc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d9aa1576 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5649: #0: 000000001d616490 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000865e3bcf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5650: #0: 00000000c8214d1d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000782baf35 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1008 Comm: khungtaskd Not tainted 4.19.0-rc8-next-20181019+ #99 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot.