INFO: task syz-executor.0:21293 blocked for more than 143 seconds. Not tainted 5.2.0+ #55 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28208 21293 8674 0x00004004 Call Trace: context_switch kernel/sched/core.c:3252 [inline] __schedule+0x7c5/0x1560 kernel/sched/core.c:3878 schedule+0xa8/0x260 kernel/sched/core.c:3942 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783 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 kthread_stop+0x10b/0x6c0 kernel/kthread.c:559 io_sq_thread_stop fs/io_uring.c:2249 [inline] io_finish_async+0x73/0x140 fs/io_uring.c:2256 io_ring_ctx_free fs/io_uring.c:2767 [inline] io_ring_ctx_wait_and_kill+0x133/0x600 fs/io_uring.c:2831 io_uring_release+0x42/0x50 fs/io_uring.c:2839 __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:185 [inline] exit_to_usermode_loop+0x309/0x370 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4134b1 Code: cf 48 c1 e9 03 4c 8b 05 a5 1c 3b 01 48 c1 ef 05 49 29 f8 49 8d 78 ff 48 83 e1 03 48 83 fa 10 0f 84 a7 04 00 00 44 0f b6 43 17 <41> f6 c0 40 0f 85 58 04 00 00 4c 8b 03 48 8b 44 24 68 49 39 c0 0f RSP: 002b:00007fffb7ff99f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004134b1 RDX: 0000001b31d20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000069720dfa R09: 0000000069720dfe R10: 00007fffb7ff9ad0 R11: 0000000000000293 R12: 000000000075bf20 R13: 000000000003e88e R14: 00000000007604b0 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1046: #0: 00000000cab6b8df (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5257 1 lock held by rsyslogd/8545: #0: 0000000097d86d24 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8634: #0: 00000000a5639516 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007cf1a0ba (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8635: #0: 000000003d053628 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008c506abf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8636: #0: 00000000840d7eba (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000053a87520 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8637: #0: 00000000ce56da64 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000076922c5e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8638: #0: 000000005baf94b7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000031b26ff1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8639: #0: 00000000d215f7b7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005f9e7946 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8640: #0: 00000000537a4e58 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003c22b9d0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1046 Comm: khungtaskd Not tainted 5.2.0+ #55 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+0x1ca/0x242 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+0x9b7/0xec0 kernel/hung_task.c:289 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8773 Comm: kworker/u4:6 Not tainted 5.2.0+ #55 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_release kernel/locking/lockdep.c:4196 [inline] RIP: 0010:lock_release+0x2fc/0x930 kernel/locking/lockdep.c:4432 Code: 03 0f b6 14 11 84 d2 74 09 80 fa 03 0f 8e bf 05 00 00 66 83 68 22 10 66 f7 40 22 f0 ff 0f 85 32 01 00 00 4c 89 ce 41 8b 56 c0 <48> b9 00 00 00 00 00 fc ff df 48 c1 ee 03 0f b6 0c 0e 84 c9 74 09 RSP: 0018:ffff888087f6fc00 EFLAGS: 00000046 RAX: ffff888096610d20 RBX: 1ffff11010fedf85 RCX: 0000000000000000 RDX: 0000000000000002 RSI: ffff888096610cc8 RDI: ffff888096610d42 RBP: ffff888087f6fcd0 R08: 0000000000000003 R09: ffff888096610cc8 R10: ffffed1015d06c73 R11: ffff8880ae83639b R12: ffffffff88da9980 R13: ffffffff8703f9ea R14: ffff888087f6fca8 R15: ffff888096610440 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000efb4c0 CR3: 000000009aea9000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:213 [inline] rcu_read_unlock include/linux/rcupdate.h:646 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x225/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x989/0x16d0 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352