kworker/dying (3396) used greatest stack depth: 12832 bytes left INFO: task syz-executor1:15706 blocked for more than 120 seconds. Not tainted 4.14.0-mm1+ #25 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D20104 15706 15704 0x80000006 Call Trace: context_switch kernel/sched/core.c:2799 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 schedule+0xf5/0x430 kernel/sched/core.c:3434 io_schedule+0x1c/0x70 kernel/sched/core.c:5042 wait_on_page_bit_common+0x4b3/0x770 mm/filemap.c:1099 wait_on_page_bit mm/filemap.c:1132 [inline] wait_on_page_writeback include/linux/pagemap.h:546 [inline] __filemap_fdatawait_range+0x27d/0x420 mm/filemap.c:533 filemap_fdatawait_range mm/filemap.c:558 [inline] filemap_fdatawait include/linux/fs.h:2596 [inline] filemap_write_and_wait+0x7a/0xd0 mm/filemap.c:624 __sync_blockdev fs/block_dev.c:448 [inline] sync_blockdev.part.27+0x50/0x70 fs/block_dev.c:457 sync_blockdev fs/block_dev.c:444 [inline] __blkdev_put+0x176/0x7c0 fs/block_dev.c:1763 blkdev_put+0x85/0x4f0 fs/block_dev.c:1835 blkdev_close+0x91/0xc0 fs/block_dev.c:1842 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ae0 kernel/exit.c:869 do_group_exit+0x149/0x400 kernel/exit.c:972 get_signal+0x73f/0x16c0 kernel/signal.c:2335 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x94/0x96 RIP: 0033:0x452879 RSP: 002b:00007f6d1a39fbe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000028 RAX: 0000000000001600 RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000020a30ff8 RSI: 0000000000000016 RDI: 0000000000000014 RBP: 000000000000043e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000140000001 R11: 0000000000000212 R12: 00000000006f3670 R13: 00000000ffffffff R14: 00007f6d1a3a06d4 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/670: #0: (rcu_read_lock){....}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554 2 locks held by getty/3018: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3019: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3020: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3021: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3022: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3023: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 3 locks held by kworker/u4:9/8760: #0: ((wq_completion)"writeback"){+.+.}, at: [] __write_once_size include/linux/compiler.h:212 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [] atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [] atomic_long_set include/asm-generic/atomic-long.h:57 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [] set_work_data kernel/workqueue.c:618 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:645 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [] process_one_work+0xad4/0x1be0 kernel/workqueue.c:2083 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [] process_one_work+0xb2f/0x1be0 kernel/workqueue.c:2087 #2: (&type->s_umount_key#31){++++}, at: [] trylock_super+0x20/0x100 fs/super.c:396 2 locks held by getty/15673: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 1 lock held by syz-executor1/15706: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xa7/0x7c0 fs/block_dev.c:1757 1 lock held by blkid/15711: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 670 Comm: khungtaskd Not tainted 4.14.0-mm1+ #25 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+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:437 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.0-mm1+ #25 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801da38c300 task.stack: ffff8801da390000 RIP: 0010:trace_hardirqs_off_thunk+0x0/0x1c RSP: 0018:ffff8801db507ff0 EFLAGS: 00000056 RAX: dffffc0000000000 RBX: 1ffff1003b472fb8 RCX: 0000000000000000 RDX: 1ffffffff0bd970c RSI: 0000000000000001 RDI: ffff8801da397cf8 RBP: ffff8801da397cf9 R08: ffffffff85bdeae8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801da397e60 R14: ffffffff865dfc20 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c436067000 CR3: 00000001d1cb0000 CR4: 00000000001406e0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: Code: bd 68 fd ff ff e8 f2 5c a6 00 e9 05 f1 ff ff 55 48 89 e5 57 56 52 51 50 41 50 41 51 41 52 41 53 48 8b 7d 08 e8 f3 84 55 00 eb 34 <55> 48 89 e5 57 56 52 51 50 41 50 41 51 41 52 41 53 48 8b 7d 08