INFO: task syz-executor.5:16337 blocked for more than 143 seconds. Not tainted 5.4.0-rc5-next-20191031 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28160 16337 8796 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:926 io_finish_async+0x102/0x180 fs/io_uring.c:3080 io_ring_ctx_free fs/io_uring.c:3861 [inline] io_ring_ctx_wait_and_kill+0x24f/0x700 fs/io_uring.c:3929 io_uring_release+0x42/0x50 fs/io_uring.c:3937 __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: 0033:0x413ae1 Code: 39 c2 0f 84 0c 02 00 00 48 85 d2 0f 84 86 02 00 00 48 89 d3 31 d2 48 f7 f3 48 c7 44 24 30 00 00 00 00 48 c7 44 24 38 00 00 00 <00> 48 c7 44 24 40 00 00 00 00 48 c7 44 24 48 00 00 00 00 48 c7 44 RSP: 002b:00007ffe9345ec50 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000413ae1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000001 R08: 00000000f13b67ce R09: ffffffffffffffff R10: 00007ffe9345ed30 R11: 0000000000000293 R12: 000000000075bf20 R13: 000000000016f4da R14: 00000000007606d8 R15: 000000000075bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1077: #0: ffffffff88faba40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 2 locks held by getty/8744: #0: ffff8880a8364090 (&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/8745: #0: ffff888094587090 (&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/8746: #0: ffff888098c08090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8747: #0: ffff88809a0d3090 (&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/8748: #0: ffff88808d82e090 (&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/8749: #0: ffff8880a5f6b090 (&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/8750: #0: ffff88809ab1a090 (&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 2 locks held by kworker/u4:4/14960: #0: ffff8880ae934d58 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #0: ffff8880ae934d58 (&rq->lock){-.-.}, at: __schedule+0x266/0x1e70 kernel/sched/core.c:4018 #1: ffffffff88faba40 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5698 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1077 Comm: khungtaskd Not tainted 5.4.0-rc5-next-20191031 #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+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+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: 14960 Comm: kworker/u4:4 Not tainted 5.4.0-rc5-next-20191031 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:68 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x50 kernel/kcov.c:102 Code: 2d 90 e9 ff 48 c7 05 de ac 3d 09 00 00 00 00 e9 77 e9 ff ff 90 90 90 90 90 90 90 90 90 55 48 89 e5 65 48 8b 04 25 80 fe 01 00 <65> 8b 15 a4 98 8e 7e 81 e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 00 RSP: 0018:ffff8880943d7bf0 EFLAGS: 00000002 RAX: ffff88809e438140 RBX: 0000000000000001 RCX: ffffffff8349563c RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff8880943d7bf0 R08: ffff88809e438140 R09: ffffed100e35b231 R10: ffffed100e35b230 R11: ffff888071ad9183 R12: ffffffff87aa1740 R13: ffff88809e438140 R14: ffffffff873a0500 R15: 0000000000000050 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff18c4cf000 CR3: 00000000a0f21000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __this_cpu_preempt_check+0x35/0x190 lib/smp_processor_id.c:65 __local_bh_enable_ip+0x1e9/0x270 kernel/softirq.c:184 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x2c/0x30 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:383 [inline] batadv_nc_purge_paths+0x265/0x370 net/batman-adv/network-coding.c:470 batadv_nc_worker+0x2ca/0x760 net/batman-adv/network-coding.c:721 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