INFO: task syz-executor.0:19256 can't die for more than 143 seconds. syz-executor.0 R running task 26552 19256 8922 0x00004006 Call Trace: Showing all locks held in the system: 1 lock held by khungtaskd/1054: #0: 0000000076762ef7 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e /kernel/locking/lockdep.c:5257 1 lock held by rsyslogd/8795: #0: 00000000818ee309 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 /fs/file.c:801 2 locks held by getty/8885: #0: 0000000065608bcd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 000000002ce80787 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/8886: #0: 0000000055ad3311 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 00000000523c4ee0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/8887: #0: 00000000eaeacec0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 00000000087bab71 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/8888: #0: 00000000d9f5bcf0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 00000000cd202729 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/8889: #0: 0000000065f72742 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 00000000f72cfe5d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/8890: #0: 00000000d1b81d20 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 000000006ed3a678 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 2 locks held by getty/8891: #0: 000000005973dd28 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 /drivers/tty/tty_ldsem.c:341 #1: 00000000f51b7e08 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 /drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:2/22946: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1054 Comm: khungtaskd Not tainted 5.2.0-next-20190718 #41 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+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:249 [inline] watchdog+0xc54/0x1320 /kernel/hung_task.c:333 kthread+0x361/0x430 /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: 22946 Comm: kworker/u4:2 Not tainted 5.2.0-next-20190718 #41 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:rcu_read_unlock_sched_notrace /./include/linux/rcupdate.h:730 [inline] RIP: 0010:trace_lock_release /./include/trace/events/lock.h:58 [inline] RIP: 0010:lock_release+0x622/0x960 /kernel/locking/lockdep.c:4431 Code: ff 05 fa 2b a9 7e 48 8b 05 13 b5 48 08 e8 96 38 06 00 85 c0 74 0d 80 3d 81 5a 48 08 00 0f 84 8a 01 00 00 65 ff 0d d6 2b a9 7e <0f> 85 87 fb ff ff e8 f4 94 a7 ff e9 7d fb ff ff 0f 0b 0f 0b 0f 0b RSP: 0018:ffff88805a3dfc00 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 1ffff1100b47bf85 RCX: 1ffffffff134aa3e RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8880a5c4a914 RBP: ffff88805a3dfcd0 R08: 1ffffffff134a3ff R09: fffffbfff134a400 R10: fffffbfff134a3ff R11: ffffffff89a51fff R12: ffffffff88dac080 R13: ffffffff871df26a R14: ffff88805a3dfca8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8b100a16a0 CR3: 00000000a8b8f000 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+0x9af/0x1740 /kernel/workqueue.c:2269 worker_thread+0x98/0xe40 /kernel/workqueue.c:2415 kthread+0x361/0x430 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352