INFO: task syz.0.1138:12331 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1138      state:D stack:27208 pid:12331 tgid:12327 ppid:11996  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 bdev_open+0xe0/0xd30
 blkdev_open+0x457/0x600
 do_dentry_open+0x953/0x13f0
 vfs_open+0x3b/0x340
 path_openat+0x2ee5/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffba018d510
RSP: 002b:00007ffba100eb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000200 RCX: 00007ffba018d510
RDX: 0000000000000200 RSI: 00007ffba100ec10 RDI: 00000000ffffff9c
RBP: 00007ffba100ec10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007ffba03d6038 R14: 00007ffba03d5fa0 R15: 00007ffce3da7428
 </TASK>
INFO: task syz.0.1138:12333 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1138      state:D stack:28936 pid:12333 tgid:12327 ppid:11996  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 bdev_open+0xe0/0xd30
 bdev_file_open_by_dev+0x1be/0x240
 setup_bdev_super+0x5a/0x5b0
 get_tree_bdev_flags+0x366/0x4d0
 vfs_get_tree+0x92/0x2b0
 do_new_mount+0x2a2/0x9e0
 __se_sys_mount+0x317/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffba018eba9
RSP: 002b:00007ffba0fee038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffba03d6090 RCX: 00007ffba018eba9
RDX: 0000200000000080 RSI: 0000200000000000 RDI: 0000200000000280
RBP: 00007ffba0211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000003008006 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffba03d6128 R14: 00007ffba03d6090 R15: 00007ffce3da7428
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
5 locks held by kworker/0:2/1272:
 #0: ffff88801bbef948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90007557bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88810a8ef198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff8881101f5198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff88801ff5a160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
2 locks held by getty/5677:
 #0: ffff8880217bf0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by udevd/5862:
 #0: ffff8880209d7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
3 locks held by kworker/u8:3/5885:
2 locks held by kworker/0:9/8574:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90001c4fbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
4 locks held by kworker/0:10/8575:
3 locks held by kworker/1:9/8692:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000272fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888023860240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x26b/0x3180
1 lock held by syz.0.1138/12331:
 #0: ffff8880209d7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by syz.0.1138/12333:
 #0: ffff88812432c0e0 (&type->s_umount_key#109/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970
 #1: ffff8880209d7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.3.1435/14028:
 #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14028 Comm: syz.3.1435 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:debug_check_no_obj_freed+0x212/0x470
Code: c0 0f 84 45 02 00 00 4d 89 fe 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df 41 80 3c 06 00 74 08 4c 89 ff e8 71 94 52 fd 49 8b 07 <48> 89 44 24 18 4d 8d 67 18 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00
RSP: 0018:ffffc9000608f7f8 EFLAGS: 00000046
RAX: ffff8880342c04d0 RBX: 0000000000000003 RCX: dffffc0000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9000608f6e0
RBP: ffff88803477ca80 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000c11edc R12: ffff888049846830
R13: ffff8881243c7000 R14: 1ffff110068580bd R15: ffff8880342c05e8
FS:  00007fbdd1c7e6c0(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c4348f9 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __free_frozen_pages+0x4dd/0xd30
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbdd0dc1465
Code: Unable to access opcode bytes at 0x7fbdd0dc143b.
RSP: 002b:00007fbdd1c7df80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fbdd0fd5fa0 RCX: 00007fbdd0dc1465
RDX: 00007fbdd1c7dfc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fbdd0e11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007fbdd0fd6038 R14: 00007fbdd0fd5fa0 R15: 00007ffcf8faacc8
 </TASK>
