INFO: task syz-executor.4:20771 can't die for more than 143 seconds. syz-executor.4 R running task 26784 20771 20762 0x80004006 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17d0 kernel/sched/core.c:3937 INFO: task syz-executor.4:20772 can't die for more than 143 seconds. syz-executor.4 R running task 27744 20772 20762 0x80004006 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17d0 kernel/sched/core.c:3937 Showing all locks held in the system: 1 lock held by khungtaskd/1062: #0: ffffffff88fa9ac0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5337 1 lock held by udevd/3883: 1 lock held by rsyslogd/8129: #0: ffff88808edc6ae0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8218: #0: ffff88808c3b0950 (&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+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8219: #0: ffff88808bd24350 (&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/8220: #0: ffff8880a058e110 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f5b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8221: #0: ffff88808d7cc9d0 (&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/8222: #0: ffff88808bd24bd0 (&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/8223: #0: ffff8880a058e990 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f572e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8224: #0: ffff8880a3f42690 (&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+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1062 Comm: khungtaskd Not tainted 5.3.0-rc5-next-20190820 #69 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:269 [inline] watchdog+0xc99/0x1360 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: 20569 Comm: kworker/u4:2 Not tainted 5.3.0-rc5-next-20190820 #69 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:102 Code: 90 90 90 90 55 48 89 e5 65 48 8b 04 25 80 fe 01 00 65 8b 15 b4 ce 8f 7e 81 e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 f8 12 00 00 <83> fa 02 75 20 48 8b 88 00 13 00 00 8b 80 fc 12 00 00 48 8b 11 48 RSP: 0000:ffff88805b1e7c68 EFLAGS: 00000246 RAX: ffff888058e74440 RBX: 0000000000000001 RCX: ffffffff833fdcce RDX: 0000000000000000 RSI: ffffffff833fdcdc RDI: 0000000000000005 RBP: ffff88805b1e7c68 R08: ffff888058e74440 R09: ffffed1015d26af5 R10: ffffed1015d26af4 R11: ffff8880ae9357a3 R12: 0000000000000001 R13: 0000000000000148 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c422fccc08 CR3: 0000000094939000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_smp_processor_id+0x3c/0x214 lib/smp_processor_id.c:57 rcu_dynticks_curr_cpu_in_eqs+0x17/0xb0 kernel/rcu/tree.c:299 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:901 rcu_read_unlock include/linux/rcupdate.h:649 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x485/0x760 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