INFO: task syz-executor.1:4008 can't die for more than 143 seconds. syz-executor.1 D28744 4008 6906 0x00004004 Call Trace: context_switch kernel/sched/core.c:3445 [inline] __schedule+0x8b4/0x1e80 kernel/sched/core.c:4169 schedule+0xd0/0x2a0 kernel/sched/core.c:4244 schedule_timeout+0x1d8/0x250 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+0x163/0x260 kernel/sched/completion.c:138 flush_workqueue+0x3ff/0x13e0 kernel/workqueue.c:2832 nbd_start_device_ioctl drivers/block/nbd.c:1325 [inline] __nbd_ioctl drivers/block/nbd.c:1400 [inline] nbd_ioctl+0x7ac/0xb77 drivers/block/nbd.c:1440 __blkdev_driver_ioctl block/ioctl.c:224 [inline] blkdev_ioctl+0x255/0x6c0 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: 0033:0x45cb29 Code: Bad RIP value. RSP: 002b:00007fab26ffbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e9c20 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000417 R14: 00000000004c6e7d R15: 00007fab26ffc6d4 INFO: task syz-executor.1:4008 blocked for more than 143 seconds. Not tainted 5.8.0-rc3-next-20200701-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28744 4008 6906 0x00004004 Call Trace: context_switch kernel/sched/core.c:3445 [inline] __schedule+0x8b4/0x1e80 kernel/sched/core.c:4169 schedule+0xd0/0x2a0 kernel/sched/core.c:4244 schedule_timeout+0x1d8/0x250 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+0x163/0x260 kernel/sched/completion.c:138 flush_workqueue+0x3ff/0x13e0 kernel/workqueue.c:2832 nbd_start_device_ioctl drivers/block/nbd.c:1325 [inline] __nbd_ioctl drivers/block/nbd.c:1400 [inline] nbd_ioctl+0x7ac/0xb77 drivers/block/nbd.c:1440 __blkdev_driver_ioctl block/ioctl.c:224 [inline] blkdev_ioctl+0x255/0x6c0 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: 0033:0x45cb29 Code: Bad RIP value. RSP: 002b:00007fab26ffbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e9c20 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000417 R14: 00000000004c6e7d R15: 00007fab26ffc6d4 Showing all locks held in the system: 1 lock held by khungtaskd/1150: #0: ffffffff89bc3000 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 1 lock held by in:imklog/6486: #0: ffff888097596b30 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:928 2 locks held by agetty/6641: #0: ffff8880935fe098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000f542e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 2 locks held by kworker/u5:1/4789: #0: ffff8880453b8138 ((wq_completion)knbd1-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880453b8138 ((wq_completion)knbd1-recv){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880453b8138 ((wq_completion)knbd1-recv){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880453b8138 ((wq_completion)knbd1-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8880453b8138 ((wq_completion)knbd1-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8880453b8138 ((wq_completion)knbd1-recv){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240 #1: ffffc90004a07da8 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244 1 lock held by syz-executor.2/31710: #0: ffffffff8a029670 (key_types_sem){++++}-{3:3}, at: key_type_lookup+0x1a/0xf0 security/keys/key.c:704 1 lock held by syz-executor.2/31728: #0: ffffffff8a029670 (key_types_sem){++++}-{3:3}, at: key_type_lookup+0x1a/0xf0 security/keys/key.c:704 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1150 Comm: khungtaskd Not tainted 5.8.0-rc3-next-20200701-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+0x1b3/0x223 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+0xd89/0xf30 kernel/hung_task.c:339 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3868 Comm: systemd-journal Not tainted 5.8.0-rc3-next-20200701-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hlock_class kernel/locking/lockdep.c:174 [inline] RIP: 0010:mark_lock+0x9b/0x1710 kernel/locking/lockdep.c:3937 Code: 48 89 04 24 49 89 f6 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 6c 11 00 00 41 0f b7 5e 20 <66> 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 f8 06 48 8d RSP: 0018:ffffc90001477a10 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000484 RCX: 0000000000000000 RDX: 1ffff1101273d147 RSI: ffff8880939e8a18 RDI: ffff8880939e8140 RBP: ffff8880939e8140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003 R13: dffffc0000000000 R14: ffff8880939e8a18 R15: 0000000000000000 FS: 00007f0dd087e8c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0dcd6a3000 CR3: 0000000093c03000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:3609 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3627 [inline] lockdep_hardirqs_on_prepare+0x1bc/0x590 kernel/locking/lockdep.c:3686 trace_hardirqs_on+0x5f/0x220 kernel/trace/trace_preemptirq.c:49 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 spin_unlock_irq include/linux/spinlock.h:404 [inline] shmem_undo_range+0x7ea/0x1a80 mm/shmem.c:991 shmem_truncate_range mm/shmem.c:996 [inline] shmem_setattr+0x67a/0xc70 mm/shmem.c:1055 notify_change+0xb6f/0x1020 fs/attr.c:336 do_truncate+0x134/0x1f0 fs/open.c:64 do_sys_ftruncate+0x4a0/0x570 fs/open.c:195 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f0dcfb41ec7 Code: Bad RIP value. RSP: 002b:00007fffcc036ab8 EFLAGS: 00000202 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007fffcc036af0 RCX: 00007f0dcfb41ec7 RDX: 00005603975c7e80 RSI: 0000000001000000 RDI: 0000000000000010 RBP: 00007fffcc036ae8 R08: 0000000000000008 R09: 00005603975c825c R10: 00005603975c81e0 R11: 0000000000000202 R12: 00005603975c81e0 R13: 00007fffcc036be8 R14: 00005603963a0958 R15: 0005a9856d71ab56