block nbd0: Device being setup by another task block nbd0: Device being setup by another task block nbd0: Device being setup by another task block nbd0: Device being setup by another task INFO: task syz-executor187:21723 blocked for more than 140 seconds. Not tainted 4.14.217-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor187 D29072 21723 7995 0x80000002 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 io_schedule+0xb5/0x120 kernel/sched/core.c:5032 wait_on_page_bit_common mm/filemap.c:1025 [inline] __lock_page+0x27b/0x380 mm/filemap.c:1197 lock_page include/linux/pagemap.h:479 [inline] truncate_inode_pages_range+0x8d2/0x13e0 mm/truncate.c:399 kill_bdev fs/block_dev.c:98 [inline] __blkdev_put+0x24c/0x800 fs/block_dev.c:1797 blkdev_close+0x86/0xb0 fs/block_dev.c:1875 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa44/0x2850 kernel/exit.c:868 do_group_exit+0x100/0x2e0 kernel/exit.c:965 get_signal+0x38d/0x1ca0 kernel/signal.c:2423 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x44a529 RSP: 002b:00007f79c30d1db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00000000006dbc68 RCX: 000000000044a529 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dbc68 RBP: 00000000006dbc60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc6c R13: 00007ffdd6e188ff R14: 00007f79c30d29c0 R15: 20c49ba5e353f7cf INFO: task systemd-udevd:21725 blocked for more than 140 seconds. Not tainted 4.14.217-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28624 21725 4633 0x00000104 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 blkdev_get+0x88/0x890 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fe926fd0840 RSP: 002b:00007ffe2aa0ac18 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00005621d54376c0 RCX: 00007fe926fd0840 RDX: 00005621d3ea6fe3 RSI: 00000000000a0800 RDI: 00005621d54390e0 RBP: 00007ffe2aa0ad90 R08: 00005621d3ea6670 R09: 0000000000000010 R10: 00005621d3ea6d0c R11: 0000000000000246 R12: 00007ffe2aa0ace0 R13: 00005621d5435c20 R14: 0000000000000003 R15: 000000000000000e Showing all locks held in the system: 1 lock held by khungtaskd/1530: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/7671: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 1 lock held by syz-executor187/21723: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xd8/0x800 fs/block_dev.c:1790 1 lock held by systemd-udevd/21725: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1530 Comm: khungtaskd Not tainted 4.14.217-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4615 Comm: systemd-journal Not tainted 4.14.217-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a1958600 task.stack: ffff8880a1960000 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x6d/0xe0 kernel/locking/spinlock.c:192 RSP: 0018:ffff8880a1967958 EFLAGS: 00000097 RAX: 0000000080000000 RBX: 0000000000000082 RCX: 0000000000000000 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffffff8c09acc8 R08: ffffffff8b9b4440 R09: 0000000000000001 R10: 0000000000000000 R11: ffff8880a1958600 R12: ffff888094692000 R13: 0000000000000000 R14: ffffffff8c09acc8 R15: 0000000000000000 FS: 00007f1910fff8c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f190e006010 CR3: 00000000a1996000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:760 [inline] debug_check_no_obj_freed+0x2c0/0x680 lib/debugobjects.c:776 free_pages_prepare mm/page_alloc.c:1064 [inline] __free_pages_ok+0x215/0xeb0 mm/page_alloc.c:1262 slab_destroy mm/slab.c:1723 [inline] slabs_destroy+0x90/0xd0 mm/slab.c:1739 cache_flusharray mm/slab.c:3483 [inline] ___cache_free+0x213/0x2c0 mm/slab.c:3525 qlink_free mm/kasan/quarantine.c:147 [inline] qlist_free_all+0x79/0x140 mm/kasan/quarantine.c:166 quarantine_reduce+0x185/0x200 mm/kasan/quarantine.c:259 kasan_kmalloc+0xa2/0x160 mm/kasan/kasan.c:536 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc mm/slab.c:3390 [inline] kmem_cache_alloc+0x111/0x3c0 mm/slab.c:3550 prepare_creds+0x39/0x490 kernel/cred.c:255 SYSC_faccessat fs/open.c:365 [inline] SyS_faccessat+0x7b/0x680 fs/open.c:353 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f19102bb9c7 RSP: 002b:00007ffd8a8cccb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffd8a8cfce0 RCX: 00007f19102bb9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000560930f3c9a3 RBP: 00007ffd8a8cce00 R08: 0000560930f323e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00005609317508a0 R15: 00007ffd8a8cd2f0 Code: 72 48 83 3d 3d a3 cf 01 00 74 64 48 89 df 57 9d 0f 1f 44 00 00 e8 e4 00 20 fa bf 01 00 00 00 e8 8a 1a 18 fa 65 8b 05 a3 ef e0 78 <85> c0 74 39 5b 5d c3 e8 57 73 20 fa 48 c7 c0 88 92 f0 88 48 ba