INFO: task syz-executor.5:18305 can't die for more than 143 seconds. syz-executor.5 D28520 18305 7393 0x00004004 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8f3/0x1f80 kernel/sched/core.c:4155 schedule+0xd0/0x2a0 kernel/sched/core.c:4230 schedule_timeout+0x454/0x850 kernel/time/timer.c:1873 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+0x7aa/0xb75 drivers/block/nbd.c:1437 __blkdev_driver_ioctl block/ioctl.c:224 [inline] blkdev_ioctl+0x25e/0x6c0 block/ioctl.c:620 block_ioctl+0xf9/0x140 fs/block_dev.c:1987 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ca59 Code: Bad RIP value. RSP: 002b:00007f3f99325c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e98c0 RCX: 000000000045ca59 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000415 R14: 00000000004c6d6f R15: 00007f3f993266d4 INFO: task syz-executor.5:18305 blocked for more than 143 seconds. Not tainted 5.7.0-rc7-next-20200529-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28520 18305 7393 0x00004004 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8f3/0x1f80 kernel/sched/core.c:4155 schedule+0xd0/0x2a0 kernel/sched/core.c:4230 schedule_timeout+0x454/0x850 kernel/time/timer.c:1873 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+0x7aa/0xb75 drivers/block/nbd.c:1437 __blkdev_driver_ioctl block/ioctl.c:224 [inline] blkdev_ioctl+0x25e/0x6c0 block/ioctl.c:620 block_ioctl+0xf9/0x140 fs/block_dev.c:1987 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ca59 Code: Bad RIP value. RSP: 002b:00007f3f99325c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e98c0 RCX: 000000000045ca59 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000415 R14: 00000000004c6d6f R15: 00007f3f993266d4 Showing all locks held in the system: 1 lock held by khungtaskd/1145: #0: ffffffff89bbde00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 2 locks held by kworker/u5:2/18268: #0: ffff88809fed6138 ((wq_completion)knbd5-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88809fed6138 ((wq_completion)knbd5-recv){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88809fed6138 ((wq_completion)knbd5-recv){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88809fed6138 ((wq_completion)knbd5-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88809fed6138 ((wq_completion)knbd5-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88809fed6138 ((wq_completion)knbd5-recv){+.+.}-{0:0}, at: process_one_work+0x844/0x1690 kernel/workqueue.c:2239 #1: ffffc90004c17dc0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x878/0x1690 kernel/workqueue.c:2243 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1145 Comm: khungtaskd Not tainted 5.7.0-rc7-next-20200529-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e6/0x221 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xf97/0x14e0 kernel/hung_task.c:339 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 250 Comm: kworker/u4:5 Not tainted 5.7.0-rc7-next-20200529-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:mark_lock+0x134/0xdd0 kernel/locking/lockdep.c:3926 Code: 48 89 14 24 48 c1 f8 06 48 8d 3c c5 20 8a 58 8c e8 71 09 59 00 48 8b 14 24 48 0f a3 15 25 b9 ff 0a 41 be 01 00 00 00 0f 92 c0 <44> 89 e1 41 d3 e6 84 c0 4d 63 f6 0f 84 b7 00 00 00 48 69 d2 b8 00 RSP: 0018:ffffc900017a7b00 EFLAGS: 00000047 RAX: 0000000000000001 RBX: 1ffff920002f4f64 RCX: ffffffff8158d0ef RDX: 000000000000062f RSI: 0000000000000008 RDI: ffffffff8c588ae0 RBP: ffff8880a8bccc80 R08: 0000000000000001 R09: fffffbfff18b115d R10: ffffffff8c588ae7 R11: fffffbfff18b115c R12: 0000000000000006 R13: ffff8880a8bcc380 R14: 0000000000000001 R15: ffff8880a8bccca0 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f36b1ce5008 CR3: 0000000096c85000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:3609 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3635 [inline] lockdep_hardirqs_on_prepare+0x3a2/0x590 kernel/locking/lockdep.c:3686 trace_hardirqs_on+0x5f/0x220 kernel/trace/trace_preemptirq.c:49 __local_bh_enable_ip+0x159/0x270 kernel/softirq.c:194 spin_unlock_bh include/linux/spinlock.h:398 [inline] batadv_nc_purge_paths+0x264/0x380 net/batman-adv/network-coding.c:470 batadv_nc_worker+0x28d/0x760 net/batman-adv/network-coding.c:719 process_one_work+0x965/0x1690 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293