INFO: task syz-executor.0:10391 blocked for more than 143 seconds. Not tainted 5.9.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28872 pid:10391 ppid: 6914 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0xec9/0x2280 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 flush_workqueue+0x3ff/0x13e0 kernel/workqueue.c:2832 nbd_start_device_ioctl drivers/block/nbd.c:1330 [inline] __nbd_ioctl drivers/block/nbd.c:1407 [inline] nbd_ioctl+0x7ac/0xbc4 drivers/block/nbd.c:1447 __blkdev_driver_ioctl block/ioctl.c:224 [inline] blkdev_ioctl+0x28c/0x700 block/ioctl.c:620 block_ioctl+0xf9/0x140 fs/block_dev.c:1871 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45dd99 Code: Bad RIP value. RSP: 002b:00007f8f34f3ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000012e80 RCX: 000000000045dd99 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000118c0a8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118c07c R13: 00007ffcd808961f R14: 00007f8f34f3b9c0 R15: 000000000118c07c Showing all locks held in the system: 1 lock held by khungtaskd/1171: #0: ffffffff8a067f40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5852 1 lock held by systemd-journal/3914: 1 lock held by in:imklog/6559: #0: ffff888090c858f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 2 locks held by kworker/u5:5/6979: #0: ffff8880963e4138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880963e4138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880963e4138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880963e4138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8880963e4138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8880963e4138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc90001db7da8 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 2 locks held by kworker/u4:4/7432: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1171 Comm: khungtaskd Not tainted 5.9.0-rc7-syzkaller #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+0x198/0x1fd lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd7d/0x1000 kernel/hung_task.c:295 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7432 Comm: kworker/u4:4 Not tainted 5.9.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_is_held kernel/locking/lockdep.c:4792 [inline] RIP: 0010:lock_is_held_type+0x5b/0xf0 kernel/locking/lockdep.c:5068 Code: 89 fc 31 db e8 e6 cf 34 f9 83 85 e4 08 00 00 01 49 89 c7 8b 85 e0 08 00 00 85 c0 7f 0d eb 7d 83 c3 01 3b 9d e0 08 00 00 7d 72 <48> 63 c3 4c 89 e6 48 8d 04 80 4d 8d 74 c5 00 4c 89 f7 e8 4e fc ff RSP: 0018:ffffc90002f47b68 EFLAGS: 00000093 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff815c005f RDX: dffffc0000000000 RSI: ffffffff8a067e80 RDI: ffff888093dbae28 RBP: ffff888093dba540 R08: 0000000000000000 R09: ffffffff8b59694f R10: fffffbfff16b2d29 R11: 0000000000000000 R12: ffffffff8a067e80 R13: ffff888093dbae28 R14: ffff888093dbae28 R15: 0000000000000286 FS: 0000000000000000(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4d329ef000 CR3: 000000009d52a000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:267 [inline] rcu_read_lock_sched_held+0x3a/0xb0 kernel/rcu/update.c:136 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x6a1/0x8f0 kernel/locking/lockdep.c:5040 rcu_lock_release include/linux/rcupdate.h:246 [inline] rcu_read_unlock include/linux/rcupdate.h:688 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x7a3/0xe50 net/batman-adv/network-coding.c:718 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294