INFO: task syz-executor2:22706 blocked for more than 120 seconds. Not tainted 4.17.0-rc6+ #89 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D19840 22706 4566 0x20020004 Call Trace: context_switch kernel/sched/core.c:2859 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3501 schedule+0xef/0x430 kernel/sched/core.c:3545 io_schedule+0x1c/0x70 kernel/sched/core.c:5165 __blkdev_direct_IO_simple+0x7fc/0xfb0 fs/block_dev.c:241 blkdev_direct_IO+0xb5f/0x1100 fs/block_dev.c:428 generic_file_read_iter+0x510/0x2f00 mm/filemap.c:2341 blkdev_read_iter+0x120/0x190 fs/block_dev.c:1930 call_read_iter include/linux/fs.h:1778 [inline] generic_file_splice_read+0x552/0x910 fs/splice.c:307 do_splice_to+0x12e/0x190 fs/splice.c:880 splice_direct_to_actor+0x268/0x8d0 fs/splice.c:952 do_splice_direct+0x2cc/0x400 fs/splice.c:1061 do_sendfile+0x60f/0xe00 fs/read_write.c:1440 __do_compat_sys_sendfile fs/read_write.c:1516 [inline] __se_compat_sys_sendfile fs/read_write.c:1505 [inline] __ia32_compat_sys_sendfile+0x187/0x290 fs/read_write.c:1505 do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline] do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7fcbcb9 RSP: 002b:00000000f5fc70ac EFLAGS: 00000282 ORIG_RAX: 00000000000000bb RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000000000013 RDX: 00000000200ddff8 RSI: 0000000002000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/892: #0: 000000002a97a891 (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 000000002a97a891 (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249 #1: 000000003bba6e6d (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4398: #0: 00000000c5e61e14 (&f->f_pos_lock){+.+.}, at: __run_timers+0x16e/0xc50 kernel/time/timer.c:1658 2 locks held by getty/4488: #0: 0000000074806b48 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000392022c3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4489: #0: 00000000cbcccc9c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000aa2de505 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4490: #0: 00000000a53771dd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e2254458 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4491: #0: 00000000938302c7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000016328b0b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4492: #0: 000000009bfbff38 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000078a95c35 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4493: #0: 00000000f711ec29 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000057252faa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4494: #0: 0000000061281dcf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000de67434e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 892 Comm: khungtaskd Not tainted 4.17.0-rc6+ #89 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+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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+0xc10/0xf60 kernel/hung_task.c:249 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2386 Comm: udevd Not tainted 4.17.0-rc6+ #89 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:ep_wakeup_source fs/eventpoll.c:622 [inline] RIP: 0010:ep_send_events_proc+0x44d/0xee0 fs/eventpoll.c:1648 RSP: 0018:ffff8801caf17360 EFLAGS: 00000246 RAX: 1ffff100396b2f2d RBX: ffff8801cb597918 RCX: ffffffff81d54f01 RDX: 0000000000000000 RSI: ffffffff81d54f0f RDI: 0000000000000004 RBP: ffff8801caf17658 R08: ffff8801caf0c000 R09: 0000000000000006 R10: ffff8801caf0c000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8801caf17630 R14: 0000000000000000 R15: 0000000000000286 FS: 00007f1aa0b537a0(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001cad04000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ep_scan_ready_list+0x3ab/0xf10 fs/eventpoll.c:699 ep_send_events fs/eventpoll.c:1707 [inline] ep_poll+0x3e2/0x11d0 fs/eventpoll.c:1833 do_epoll_wait+0x1b0/0x200 fs/eventpoll.c:2191 __do_sys_epoll_wait fs/eventpoll.c:2201 [inline] __se_sys_epoll_wait fs/eventpoll.c:2198 [inline] __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2198 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f1aa0267943 RSP: 002b:00007ffe869a6ab8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007f1aa0267943 RDX: 0000000000000008 RSI: 00007ffe869a6bb0 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000001768280 R15: 0000000001765250 Code: 08 00 00 48 8b 85 70 fd ff ff 48 8b 18 48 8b 85 60 fd ff ff c6 00 00 48 8d 43 50 48 89 85 38 fd ff ff 48 c1 e8 03 42 80 3c 20 00 <0f> 85 3b 08 00 00 48 8b 85 60 fd ff ff 4c 8b 73 50 80 38 00 0f