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=-5.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, 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 E25F2C04EB8 for ; Tue, 4 Dec 2018 15:21:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BADB2081C for ; Tue, 4 Dec 2018 15:21:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BADB2081C 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 S1726870AbeLDPVF (ORCPT ); Tue, 4 Dec 2018 10:21:05 -0500 Received: from mail-it1-f197.google.com ([209.85.166.197]:58254 "EHLO mail-it1-f197.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726367AbeLDPVF (ORCPT ); Tue, 4 Dec 2018 10:21:05 -0500 Received: by mail-it1-f197.google.com with SMTP id n124so12926193itb.7 for ; Tue, 04 Dec 2018 07:21:03 -0800 (PST) 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=hlkXGEJF2m/jMDCfsOvDd/bOoVjAHYqTwyAfWUipLAU=; b=ni9cojtGGjjd5rc7pVms6Xrqv2nom3nX78B3LOY+thOAjmV1p3Ba5Ahfqu56uDuTKF N3w4VCSdmv9+gnxtwFsoNs17VlNR5/X/QZYcIJ6fDAam5RdRHzD9zXBFGuav1IEYClcT M5fvlEfZxpqJ3qI6QNSX+V7fhjeUfymxmfYb2ortg0WAqtda9gJawFbNrOUOILOUhhy9 sNLdgJ1E/kBPQNpZ5dPChnBnGdYOzgfuc3ZGIsKEAFXp7K1SMV0LZJBlDLEZtu2/2XxR 74NxiDC75HTkFBwmHb/ptRZGiq1p1+AeYZkuGp2LHxrWJo2AoS06EduDUW9kk411Qkx+ xnUQ== X-Gm-Message-State: AA+aEWa2MpWwObjApJoERTQarrSPaQEHyaydCF8LSwztDBJ9q29I39Rq kVbmVskO1v//IGXk46edTPgwbVKvxLptZg6NZWfLLLRAAhiK X-Google-Smtp-Source: AFSGD/XTRyJkZEM3sgfp7Q8FeZRt971AuhM9K0M57lRopFmltlrOHKHTOS53ZQ4RzQonYJdU7rVWqBy9cGCeCkKfmFEWUXXWlvC4 MIME-Version: 1.0 X-Received: by 2002:a24:2c4d:: with SMTP id i74mr10782944iti.12.1543936863520; Tue, 04 Dec 2018 07:21:03 -0800 (PST) Date: Tue, 04 Dec 2018 07:21:03 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000004e5428057c33d061@google.com> Subject: possible deadlock in ep_free From: syzbot To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk 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: 0072a0c14d5b Merge tag 'media/v4.20-4' of git://git.kernel.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14d2796d400000 kernel config: https://syzkaller.appspot.com/x/.config?x=b9cc5a440391cbfd dashboard link: https://syzkaller.appspot.com/bug?extid=296ea3811c64964727aa compiler: gcc (GCC) 8.0.1 20180413 (experimental) userspace arch: i386 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+296ea3811c64964727aa@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected 4.20.0-rc5+ #265 Not tainted ------------------------------------------------------ kworker/0:3/6216 is trying to acquire lock: 000000006d826351 (epmutex){+.+.}, at: ep_free+0xf6/0x300 fs/eventpoll.c:829 but task is already holding lock: 000000005098accc ((delayed_fput_work).work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 ((delayed_fput_work).work){+.+.}: process_one_work+0xc0a/0x1c40 kernel/workqueue.c:2129 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 -> #3 ((wq_completion)"events"){+.+.}: flush_workqueue+0x30a/0x1e10 kernel/workqueue.c:2655 flush_scheduled_work include/linux/workqueue.h:599 [inline] vim2m_stop_streaming+0x7c/0x2c0 drivers/media/platform/vim2m.c:811 __vb2_queue_cancel+0x171/0xd20 drivers/media/common/videobuf2/videobuf2-core.c:1823 vb2_core_queue_release+0x26/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2229 vb2_queue_release+0x15/0x20 drivers/media/common/videobuf2/videobuf2-v4l2.c:837 v4l2_m2m_ctx_release+0x2a/0x35 drivers/media/v4l2-core/v4l2-mem2mem.c:931 vim2m_release+0xe6/0x150 drivers/media/platform/vim2m.c:977 v4l2_release+0x224/0x3a0 drivers/media/v4l2-core/v4l2-dev.c:456 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 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_32_irqs_on arch/x86/entry/common.c:341 [inline] do_fast_syscall_32+0xcd5/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 -> #2 (&dev->dev_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0x166/0x16f0 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 v4l2_m2m_fop_poll+0x98/0x120 drivers/media/v4l2-core/v4l2-mem2mem.c:1105 v4l2_poll+0x153/0x200 drivers/media/v4l2-core/v4l2-dev.c:350 vfs_poll include/linux/poll.h:86 [inline] ep_item_poll.isra.15+0x15c/0x400 fs/eventpoll.c:892 ep_insert+0x781/0x1dd0 fs/eventpoll.c:1464 __do_sys_epoll_ctl fs/eventpoll.c:2121 [inline] __se_sys_epoll_ctl fs/eventpoll.c:2007 [inline] __ia32_sys_epoll_ctl+0xeda/0x1080 fs/eventpoll.c:2007 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 -> #1 (&ep->mtx){+.+.}: __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0x166/0x16f0 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 ep_free+0x160/0x300 fs/eventpoll.c:849 ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:869 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 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 -> #0 (epmutex){+.+.}: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0x166/0x16f0 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 ep_free+0xf6/0x300 fs/eventpoll.c:829 ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:869 __fput+0x385/0xa30 fs/file_table.c:278 delayed_fput+0x55/0x80 fs/file_table.c:304 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 other info that might help us debug this: Chain exists of: epmutex --> (wq_completion)"events" --> (delayed_fput_work).work Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((delayed_fput_work).work); lock((wq_completion)"events"); lock((delayed_fput_work).work); lock(epmutex); *** DEADLOCK *** 2 locks held by kworker/0:3/6216: #0: 000000000aab2aee ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:209 [inline] #0: 000000000aab2aee ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000aab2aee ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000000aab2aee ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000000aab2aee ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000000aab2aee ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000000aab2aee ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 000000005098accc ((delayed_fput_work).work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 stack backtrace: CPU: 0 PID: 6216 Comm: kworker/0:3 Not tainted 4.20.0-rc5+ #265 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events delayed_fput Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 print_circular_bug.isra.35.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2347 [inline] __lock_acquire+0x3399/0x4c20 kernel/locking/lockdep.c:3341 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0x166/0x16f0 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 ep_free+0xf6/0x300 fs/eventpoll.c:829 ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:869 __fput+0x385/0xa30 fs/file_table.c:278 delayed_fput+0x55/0x80 fs/file_table.c:304 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 audit: type=1326 audit(1543921229.079:66): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=265 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop1' (00000000b08eabe4): kobject_uevent_env audit: type=1326 audit(1543921229.079:67): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop1' (00000000b08eabe4): fill_kobj_path: path = '/devices/virtual/block/loop1' audit: type=1326 audit(1543921229.079:68): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' audit: type=1326 audit(1543921229.079:69): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921229.079:70): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop0' (00000000c90ec763): kobject_uevent_env audit: type=1326 audit(1543921229.079:71): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop0' (00000000c90ec763): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop3' (00000000287e60d6): kobject_uevent_env audit: type=1326 audit(1543921229.079:72): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop3' (00000000287e60d6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (0000000095b64449): kobject_uevent_env audit: type=1326 audit(1543921229.079:73): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' audit: type=1326 audit(1543921229.079:74): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop2' (00000000a9a0cc13): kobject_uevent_env audit: type=1326 audit(1543921229.079:75): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop2' (00000000a9a0cc13): fill_kobj_path: path = '/devices/virtual/block/loop2' audit: type=1326 audit(1543921229.079:76): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23841 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop1' (00000000b08eabe4): kobject_uevent_env kobject: 'loop1' (00000000b08eabe4): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop2' (00000000a9a0cc13): kobject_uevent_env kobject: 'loop2' (00000000a9a0cc13): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (00000000c90ec763): kobject_uevent_env kobject: 'loop0' (00000000c90ec763): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (00000000b08eabe4): kobject_uevent_env kobject: 'loop1' (00000000b08eabe4): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop4' (00000000b69c11d9): kobject_uevent_env kobject: 'loop4' (00000000b69c11d9): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop2' (00000000a9a0cc13): kobject_uevent_env kobject: 'loop2' (00000000a9a0cc13): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop0' (00000000c90ec763): kobject_uevent_env kobject: 'loop0' (00000000c90ec763): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop3' (00000000287e60d6): kobject_uevent_env kobject: 'loop3' (00000000287e60d6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop1' (00000000b08eabe4): kobject_uevent_env kobject: 'loop1' (00000000b08eabe4): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (00000000287e60d6): kobject_uevent_env kobject: 'loop3' (00000000287e60d6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (00000000b08eabe4): kobject_uevent_env kobject: 'loop1' (00000000b08eabe4): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop0' (00000000c90ec763): kobject_uevent_env kobject: 'loop0' (00000000c90ec763): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kauditd_printk_skb: 30514 callbacks suppressed audit: type=1326 audit(1543921234.119:30591): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30592): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30593): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30594): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30595): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30596): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30597): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30598): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30599): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 audit: type=1326 audit(1543921234.149:30600): auid=4294967295 uid=0 gid=0 ses=4294967295 subj==unconfined pid=23893 comm="syz-executor4" exe="/root/syz-executor4" sig=0 arch=40000003 syscall=240 compat=1 ip=0xf7f68a29 code=0x50000 kobject: 'loop4' (00000000b69c11d9): kobject_uevent_env kobject: 'loop4' (00000000b69c11d9): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop0' (00000000c90ec763): kobject_uevent_env kobject: 'loop0' (00000000c90ec763): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop2' (00000000a9a0cc13): kobject_uevent_env kobject: 'loop2' (00000000a9a0cc13): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (00000000b08eabe4): kobject_uevent_env kobject: 'loop1' (00000000b08eabe4): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (00000000287e60d6): kobject_uevent_env kobject: 'loop3' (00000000287e60d6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (00000000c90ec763): kobject_uevent_env kobject: 'loop0' (00000000c90ec763): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (00000000b08eabe4): kobject_uevent_env kobject: 'loop1' (00000000b08eabe4): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (00000000287e60d6): kobject_uevent_env kobject: 'loop3' (00000000287e60d6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (00000000b69c11d9): kobject_uevent_env kobject: 'loop4' (00000000b69c11d9): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop0' (00000000c90ec763): kobject_uevent_env kobject: 'loop0' (00000000c90ec763): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (00000000b08eabe4): kobject_uevent_env kobject: 'loop1' (00000000b08eabe4): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop2' (00000000a9a0cc13): kobject_uevent_env kobject: 'loop2' (00000000a9a0cc13): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (00000000287e60d6): kobject_uevent_env kobject: 'loop3' (00000000287e60d6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop3' (00000000287e60d6): kobject_uevent_env kobject: 'loop3' (00000000287e60d6): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop2' (00000000a9a0cc13): kobject_uevent_env kobject: 'loop2' (00000000a9a0cc13): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop5' (0000000095b64449): kobject_uevent_env kobject: 'loop5' (0000000095b64449): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (00000000c90ec763): kobject_uevent_env kobject: 'loop0' (00000000c90ec763): fill_kobj_path: path = '/devices/virtual/block/loop0' --- 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.