NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.1:11179 blocked for more than 140 seconds. Not tainted 4.14.173-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28800 11179 7446 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x946/0xe40 kernel/time/timer.c:1723 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common kernel/sched/completion.c:123 [inline] wait_for_completion+0x241/0x390 kernel/sched/completion.c:144 flush_workqueue+0x3d1/0x13f0 kernel/workqueue.c:2674 nbd_start_device_ioctl drivers/block/nbd.c:1249 [inline] __nbd_ioctl drivers/block/nbd.c:1320 [inline] nbd_ioctl+0x4e1/0xa30 drivers/block/nbd.c:1360 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x91d/0x17d0 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c849 RSP: 002b:00007f3c3b547c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f3c3b5486d4 RCX: 000000000045c849 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000007 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000402 R14: 00000000004c69f6 R15: 000000000076bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1050: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/7398: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7399: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7400: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7401: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7402: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7403: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7404: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by kworker/u5:1/9374: #0: ("knbd%d-recv"nbd->index){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("knbd%d-recv"nbd->index){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("knbd%d-recv"nbd->index){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("knbd%d-recv"nbd->index){+.+.}, at: [] process_one_work+0x727/0x1540 kernel/workqueue.c:2085 #1: ((&args->work)){+.+.}, at: [] process_one_work+0x761/0x1540 kernel/workqueue.c:2089 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1050 Comm: khungtaskd Not tainted 4.14.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e2/0xb80 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2343 Comm: kworker/u4:4 Not tainted 4.14.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880a16d2500 task.stack: ffff8880a16e0000 RIP: 0010:trace_softirqs_on+0x243/0x3b0 kernel/locking/lockdep.c:3012 RSP: 0018:ffff8880a16e7c60 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8880a16d2500 RCX: 1ffffffff14b0f60 RDX: 1ffff110142da5a9 RSI: 0000000000000000 RDI: ffff8880a16d2d7c RBP: ffff8880a16d2500 R08: 0000000000000001 R09: 0000000000000002 R10: ffff8880a16d2dd0 R11: ffff8880a16d2500 R12: ffff8880a16d2500 R13: ffffffff862808d0 R14: ffff8880580817c0 R15: ffff888058082238 FS: 0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c4204aa000 CR3: 000000008ec53000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __local_bh_enable_ip+0x118/0x190 kernel/softirq.c:173 spin_unlock_bh include/linux/spinlock.h:362 [inline] batadv_nc_purge_paths+0x257/0x360 net/batman-adv/network-coding.c:479 batadv_nc_worker+0x26a/0x6d0 net/batman-adv/network-coding.c:729 process_one_work+0x813/0x1540 kernel/workqueue.c:2114 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 01 00 00 8b 85 48 08 00 00 85 c0 0f 85 d0 00 00 00 65 48 8b 1c 25 40 ee 01 00 48 8d bb 7c 08 00 00 48 b8 00 00 00 00 00 fc ff df <48> 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38