INFO: task syz-executor3:16276 blocked for more than 120 seconds. Not tainted 4.16.0+ #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D21376 16276 4519 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 io_schedule+0x1c/0x70 kernel/sched/core.c:5115 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+0x282/0x430 mm/filemap.c:533 file_write_and_wait_range+0xd7/0x100 mm/filemap.c:756 blkdev_fsync+0x67/0xb0 fs/block_dev.c:623 vfs_fsync_range+0x110/0x260 fs/sync.c:196 generic_write_sync include/linux/fs.h:2680 [inline] blkdev_write_iter+0x2e6/0x3e0 fs/block_dev.c:1910 call_write_iter include/linux/fs.h:1782 [inline] do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653 do_iter_write+0x154/0x540 fs/read_write.c:932 vfs_iter_write+0x77/0xb0 fs/read_write.c:945 iter_file_splice_write+0x7db/0xf30 fs/splice.c:749 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x125/0x180 fs/splice.c:1018 splice_direct_to_actor+0x2c1/0x820 fs/splice.c:973 do_splice_direct+0x29b/0x3c0 fs/splice.c:1061 do_sendfile+0x5c9/0xe80 fs/read_write.c:1413 SYSC_sendfile64 fs/read_write.c:1468 [inline] SyS_sendfile64+0xbd/0x160 fs/read_write.c:1460 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4552d9 RSP: 002b:00007f15ee972c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f15ee9736d4 RCX: 00000000004552d9 RDX: 00000000200ddff8 RSI: 0000000000000014 RDI: 0000000000000013 RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000102000001 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004c5 R14: 00000000006fa318 R15: 0000000000000001 Showing all locks held in the system: 3 locks held by kworker/u4:0/5: #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000f8031ccf>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000f8031ccf>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000f8031ccf>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<00000000f8031ccf>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<0000000087db2410>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (&type->s_umount_key#34){.+.+}, at: [<0000000039f453ae>] trylock_super+0x20/0x100 fs/super.c:395 2 locks held by khungtaskd/876: #0: (rcu_read_lock){....}, at: [<00000000e8f8665e>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000e8f8665e>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000008315eac4>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4440: #0: (&tty->ldisc_sem){++++}, at: [<00000000a9ae3e09>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000087eef5fb>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4441: #0: (&tty->ldisc_sem){++++}, at: [<00000000a9ae3e09>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000087eef5fb>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4442: #0: (&tty->ldisc_sem){++++}, at: [<00000000a9ae3e09>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000087eef5fb>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4443: #0: (&tty->ldisc_sem){++++}, at: [<00000000a9ae3e09>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000087eef5fb>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4444: #0: (&tty->ldisc_sem){++++}, at: [<00000000a9ae3e09>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000087eef5fb>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4445: #0: (&tty->ldisc_sem){++++}, at: [<00000000a9ae3e09>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000087eef5fb>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4446: #0: (&tty->ldisc_sem){++++}, at: [<00000000a9ae3e09>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000087eef5fb>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 876 Comm: khungtaskd Not tainted 4.16.0+ #10 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+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 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+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2374 Comm: udevd Not tainted 4.16.0+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:335 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:332 [inline] RIP: 0010:trace_lock_release include/trace/events/lock.h:58 [inline] RIP: 0010:lock_release+0x1a2/0xa40 kernel/locking/lockdep.c:3938 RSP: 0018:ffff8801cadf7840 EFLAGS: 00000047 RAX: 0000000000000000 RBX: ffff8801cade8140 RCX: ffffffff81c414c4 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801cade89b4 RBP: ffff8801cadf7970 R08: 0000000000000000 R09: 000000000000000c R10: ffff8801cadf7850 R11: 0000000000000003 R12: ffff8801cadf7948 R13: ffff8801cadf7a68 R14: 0000000000000000 R15: 1ffff100395bef0d FS: 00007fea2e4ec7a0(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000017ea000 CR3: 00000001cb3e5004 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x1f/0xc0 kernel/locking/spinlock.c:184 spin_unlock_irqrestore include/linux/spinlock.h:365 [inline] ep_poll+0x363/0x11d0 fs/eventpoll.c:1825 SYSC_epoll_wait fs/eventpoll.c:2186 [inline] SyS_epoll_wait+0x167/0x1c0 fs/eventpoll.c:2151 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7fea2dc00943 RSP: 002b:00007fff3ca13768 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007fea2dc00943 RDX: 0000000000000008 RSI: 00007fff3ca13860 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00000000012852a0 R15: 0000000001273250 Code: d0 7c 08 84 d2 0f 85 6d 06 00 00 c7 83 74 08 00 00 01 00 00 00 0f 1f 44 00 00 65 8b 05 b8 0e aa 7e 89 c0 48 0f a3 05 9e 8a 95 07 <0f> 82 96 04 00 00 4d 8d b4 24 40 ff ff ff 48 b8 00 00 00 00 00