INFO: task syz-executor.2:23952 can't die for more than 143 seconds. syz-executor.2 D28160 23952 9124 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 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+0x247/0x470 fs/io-wq.c:922 io_finish_async+0x102/0x180 fs/io_uring.c:3085 io_ring_ctx_free fs/io_uring.c:3866 [inline] io_ring_ctx_wait_and_kill+0x24f/0x700 fs/io_uring.c:3934 io_uring_release+0x42/0x50 fs/io_uring.c:3942 __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: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+0x65f/0x760 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413db1 Code: b5 8c 01 00 e8 20 87 01 00 48 8d 05 cd 17 4c 00 48 89 04 24 48 c7 44 24 08 0c 00 00 00 e8 57 8e 01 00 e8 02 87 01 00 48 8b 44 <24> 78 48 89 04 24 e8 84 8c 01 00 e8 4f 87 01 00 e8 2a 85 01 00 48 RSP: 002b:00007ffe01f53490 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413db1 RDX: 0000001b2de20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: ffffffff8100a6a1 R09: 000000007f7cd9cc R10: 00007ffe01f53570 R11: 0000000000000293 R12: 000000000075bf20 R13: 0000000000075155 R14: 0000000000760570 R15: 000000000075bf2c INFO: task syz-executor.2:23952 blocked for more than 143 seconds. Not tainted 5.4.0-rc6-next-20191106 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28160 23952 9124 0x00004004 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 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+0x247/0x470 fs/io-wq.c:922 io_finish_async+0x102/0x180 fs/io_uring.c:3085 io_ring_ctx_free fs/io_uring.c:3866 [inline] io_ring_ctx_wait_and_kill+0x24f/0x700 fs/io_uring.c:3934 io_uring_release+0x42/0x50 fs/io_uring.c:3942 __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: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+0x65f/0x760 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413db1 Code: b5 8c 01 00 e8 20 87 01 00 48 8d 05 cd 17 4c 00 48 89 04 24 48 c7 44 24 08 0c 00 00 00 e8 57 8e 01 00 e8 02 87 01 00 48 8b 44 <24> 78 48 89 04 24 e8 84 8c 01 00 e8 4f 87 01 00 e8 2a 85 01 00 48 RSP: 002b:00007ffe01f53490 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413db1 RDX: 0000001b2de20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: ffffffff8100a6a1 R09: 000000007f7cd9cc R10: 00007ffe01f53570 R11: 0000000000000293 R12: 000000000075bf20 R13: 0000000000075155 R14: 0000000000760570 R15: 000000000075bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1078: #0: ffffffff88fab880 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 2 locks held by rsyslogd/8990: #0: ffff8880a388d6a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: ffffffff890480c0 (fs_reclaim){+.+.}, at: syslog_print kernel/printk/printk.c:1364 [inline] #1: ffffffff890480c0 (fs_reclaim){+.+.}, at: do_syslog kernel/printk/printk.c:1529 [inline] #1: ffffffff890480c0 (fs_reclaim){+.+.}, at: do_syslog+0x699/0x1870 kernel/printk/printk.c:1503 2 locks held by getty/9080: #0: ffff8880a127e090 (&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+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9081: #0: ffff8880a0710090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9082: #0: ffff8880a89aa090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f492e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9083: #0: ffff8880a3d16090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9084: #0: ffff8880a812f090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f452e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9085: #0: ffff8880a91c1090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f3d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/9086: #0: ffff88809efc3090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1078 Comm: khungtaskd Not tainted 5.4.0-rc6-next-20191106 #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:269 [inline] watchdog+0xc8f/0x1350 kernel/hung_task.c:353 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: 21 Comm: kworker/u4:1 Not tainted 5.4.0-rc6-next-20191106 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x6/0x4a00 kernel/locking/lockdep.c:3816 Code: 00 e9 6d ff ff ff 48 89 75 d0 e8 d5 61 56 00 48 8b 75 d0 eb a5 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 <45> 89 cf 48 8d 85 78 ff ff ff 41 56 49 89 fe 41 55 48 c1 e8 03 41 RSP: 0018:ffff8880a9a07bd0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff88fab880 RBP: ffff8880a9a07bd8 R08: 0000000000000000 R09: 0000000000000000 R10: fffffbfff13900b8 R11: ffffffff89c805c7 R12: ffffffff88fab880 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000a3ad0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:617 [inline] batadv_nc_process_nc_paths.part.0+0xe4/0x3c0 net/batman-adv/network-coding.c:686 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:678 [inline] batadv_nc_worker+0x5df/0x760 net/batman-adv/network-coding.c:734 process_one_work+0x9af/0x1740 kernel/workqueue.c:2263 worker_thread+0x98/0xe40 kernel/workqueue.c:2409 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352