INFO: task syz-executor.0:12889 blocked for more than 143 seconds. Not tainted 5.7.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28120 12889 7064 0x00004004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x937/0x1ff0 kernel/sched/core.c:4083 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 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+0x16a/0x270 kernel/sched/completion.c:138 flush_workqueue+0x403/0x14f0 kernel/workqueue.c:2831 nbd_start_device_ioctl drivers/block/nbd.c:1322 [inline] __nbd_ioctl drivers/block/nbd.c:1397 [inline] nbd_ioctl+0x7ae/0xb7f drivers/block/nbd.c:1437 __blkdev_driver_ioctl block/ioctl.c:322 [inline] blkdev_ioctl+0x25b/0x660 block/ioctl.c:718 block_ioctl+0xf9/0x140 fs/block_dev.c:2005 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca69 Code: Bad RIP value. RSP: 002b:00007f53c5ca0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e90c0 RCX: 000000000045ca69 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000409 R14: 00000000004c6ca4 R15: 00007f53c5ca16d4 Showing all locks held in the system: 1 lock held by khungtaskd/1143: #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 2 locks held by kworker/u5:0/1626: #0: ffff8880a81a7938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a81a7938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a81a7938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a81a7938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a81a7938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880a81a7938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880a81a7938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239 #1: ffffc900055e7dc0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 1 lock held by in:imklog/6723: #0: ffff8880a65b23f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by kworker/u4:14/8844: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1143 Comm: khungtaskd Not tainted 5.7.0-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8844 Comm: kworker/u4:14 Not tainted 5.7.0-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:__sanitizer_cov_trace_pc+0x47/0x50 kernel/kcov.c:197 Code: 90 d8 13 00 00 83 fa 02 75 20 48 8b 88 e0 13 00 00 8b 80 dc 13 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 0f 1f 84 00 00 00 00 00 65 4c 8b 04 25 00 1f 02 00 65 8b 05 98 RSP: 0018:ffffc90001947c88 EFLAGS: 00000293 RAX: ffff8880930142c0 RBX: 0000000000000001 RCX: ffffffff8399b8a6 RDX: 0000000000000000 RSI: ffffffff8399b8af RDI: 0000000000000005 RBP: ffff888052f0cc00 R08: ffff8880930142c0 R09: fffffbfff185df2d R10: ffffffff8c2ef967 R11: fffffbfff185df2c R12: 0000000000000001 R13: 000000000000017d R14: dffffc0000000000 R15: ffff888052f20be8 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f45b9551000 CR3: 00000000a6d20000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_preemption_disabled lib/smp_processor_id.c:52 [inline] debug_smp_processor_id+0x2f/0x185 lib/smp_processor_id.c:57 rcu_dynticks_curr_cpu_in_eqs+0x12/0xb0 kernel/rcu/tree.c:300 rcu_is_watching+0xc/0x20 kernel/rcu/tree.c:929 rcu_read_lock include/linux/rcupdate.h:602 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0x4c3/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351