INFO: task syz-executor812:7748 blocked for more than 140 seconds. Not tainted 4.19.73 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor812 D29512 7748 7459 0x00000000 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1780 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __do_sys_io_destroy fs/aio.c:1394 [inline] __se_sys_io_destroy fs/aio.c:1372 [inline] __x64_sys_io_destroy+0x373/0x420 fs/aio.c:1372 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x443309 Code: e8 1c 0d 03 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe720add68 EFLAGS: 00000246 ORIG_RAX: 00000000000000cf RAX: ffffffffffffffda RBX: 0000000000000064 RCX: 0000000000443309 RDX: 0000000000443309 RSI: 0000000000000000 RDI: 00007ffbec3a5000 RBP: 0000000000000000 R08: 00000000004aa947 R09: 00000000004aa947 R10: 000000000000001c R11: 0000000000000246 R12: 0000000000000046 R13: 0000000000403f80 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1037: #0: 0000000020170b6c (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/7308: #0: 0000000097a0b5c6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7430: #0: 00000000e72203cc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000009228a535 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7431: #0: 00000000e6d0335d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000a15f2bff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7432: #0: 000000007216149d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000003722e17 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7433: #0: 00000000382fcc57 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000027e538e1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7434: #0: 00000000394d9614 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000e9082120 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7435: #0: 000000003263dec9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b13ac7ec (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7436: #0: 0000000094be6fef (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000eaf521a7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1037 Comm: khungtaskd Not tainted 4.19.73 #0 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7749 Comm: syz-executor812 Not tainted 4.19.73 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__x64_sys_wait4+0x2a/0xf0 kernel/exit.c:1676 Code: 55 48 89 e5 53 48 89 fb 48 83 ec 18 e8 6f 0e 2b 00 48 8d 7b 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <75> 72 48 8d 7b 60 48 8b 4b 38 48 b8 00 00 00 00 00 fc ff df 48 89 RSP: 0018:ffff8880a8ff7ef0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff8880a8ff7f58 RCX: ffffffff8100a205 RDX: 1ffff110151feff2 RSI: ffffffff81405431 RDI: ffff8880a8ff7f90 RBP: ffff8880a8ff7f10 R08: ffff888098bea540 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a8ff7f58 R13: ffffffff88724618 R14: 0000000000000000 R15: 0000000000000000 FS: 000000000193f880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006dcb24 CR3: 0000000092847000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x402f3a Code: c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 8b 05 fe 9b 2d 00 85 c0 75 36 45 31 d2 48 63 d2 48 63 ff b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 d0 ff ff ff f7 RSP: 002b:00007ffe720add50 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000402f3a RDX: 0000000040000000 RSI: 00007ffe720add5c RDI: ffffffffffffffff RBP: 0000000000000000 R08: 00000000004aa947 R09: 00000000004aa947 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000046 R13: 0000000000403f80 R14: 0000000000000000 R15: 0000000000000000