INFO: task syz-executor.0:8410 blocked for more than 143 seconds. Not tainted 5.4.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27656 8410 8845 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x8e1/0x1f30 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871 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 io_wq_destroy+0x22a/0x450 fs/io-wq.c:1059 io_finish_async+0x128/0x1b0 fs/io_uring.c:3476 io_ring_ctx_free fs/io_uring.c:4273 [inline] io_ring_ctx_wait_and_kill+0x269/0x7a0 fs/io_uring.c:4346 io_uring_release+0x42/0x50 fs/io_uring.c:4354 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a649 Code: ec 08 10 00 00 48 89 ac 24 00 10 00 00 48 8d ac 24 00 10 00 00 48 8b 59 20 48 85 db 75 67 48 8b b4 24 20 10 00 00 8b 8c 24 28 <10> 00 00 48 89 e7 f3 a4 48 8b 94 24 18 10 00 00 ff 12 48 8b 94 24 RSP: 002b:00007fbf175e4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000021 RAX: 000000000000000a RBX: 0000000000000002 RCX: 000000000045a649 RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbf175e56d4 R13: 00000000004c0f20 R14: 00000000004d3c48 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1077: #0: ffffffff891ab580 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334 4 locks held by rs:main Q:Reg/8713: #0: ffff8880ae937318 (&rq->lock){-.-.}, at: newidle_balance+0xa28/0xe80 kernel/sched/fair.c:10166 #1: ffffffff891ab580 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5729 #2: ffff888093b9e508 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_trylock include/linux/fs.h:811 [inline] #2: ffff888093b9e508 (&sb->s_type->i_mutex_key#11){+.+.}, at: ext4_file_write_iter+0x220/0x13c0 fs/ext4/file.c:234 #3: ffffffff891ab580 (rcu_read_lock){....}, at: inode_cgwb_enabled include/linux/backing-dev.h:260 [inline] #3: ffffffff891ab580 (rcu_read_lock){....}, at: balance_dirty_pages_ratelimited+0x708/0x1ee0 mm/page-writeback.c:1875 3 locks held by rsyslogd/8715: #0: ffff88809a01b660 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: ffff8880ae937318 (&rq->lock){-.-.}, at: fs_reclaim_acquire.part.0+0x0/0x30 include/linux/uaccess.h:173 #2: ffffffff891ab580 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:435 [inline] #2: ffffffff891ab580 (rcu_read_lock){....}, at: update_curr+0x2ea/0x8d0 kernel/sched/fair.c:859 2 locks held by getty/8805: #0: ffff8880a3997090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f372e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8806: #0: ffff8880a3ead090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f532e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8807: #0: ffff8880a700d090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8808: #0: ffff88809a981090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f432e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8809: #0: ffff8880a8adb090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f2f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8810: #0: ffff88809aa15090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8811: #0: ffff8880977bf090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1077 Comm: khungtaskd Not tainted 5.4.0-syzkaller #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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:205 [inline] watchdog+0xb11/0x10c0 kernel/hung_task.c:289 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 46 Comm: kworker/1:1 Not tainted 5.4.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:__local_bh_disable_ip+0x92/0x1b0 kernel/softirq.c:128 Code: 48 c1 ea 03 80 3c 02 00 0f 85 18 01 00 00 48 83 3d 42 93 cc 07 00 0f 84 e4 00 00 00 fa 66 0f 1f 44 00 00 65 01 1d d6 7e bb 7e <65> 8b 15 cf 7e bb 7e 48 31 da 80 e6 ff 74 4e 48 c7 c2 98 32 13 89 RSP: 0018:ffff8880a9affc68 EFLAGS: 00000082 RAX: dffffc0000000000 RBX: 0000000000000200 RCX: 0000000000000000 RDX: 1ffffffff1226654 RSI: 0000000000000200 RDI: ffffffff848bd495 RBP: ffff8880a9affc80 R08: 1ffff1101535ff77 R09: ffff8880a9affbb8 R10: ffffed101535ff7e R11: ffff8880a9affbf7 R12: ffffffff848bd495 R13: 0000000000000286 R14: 0000000000000022 R15: 0000000000000022 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f284e1ec140 CR3: 00000000a0f5a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: local_bh_disable include/linux/bottom_half.h:19 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:383 [inline] nsim_dev_trap_report_work+0x77f/0xaf0 drivers/net/netdevsim/dev.c:412 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352