INFO: task syz.2.123:7345 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.123       state:D stack:25608 pid:7345  tgid:7344  ppid:7113   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8700d8ec29
RSP: 002b:00007f8701b95038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f8700fd5fa0 RCX: 00007f8700d8ec29
RDX: 0000000000000000 RSI: 0000200000000100 RDI: ffffffff80000800
RBP: 00007f8700e11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000200 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8700fd6038 R14: 00007f8700fd5fa0 R15: 00007fff3a6fae28
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5675:
 #0: ffff88810c9580a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000290e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by syz-executor/5857:
1 lock held by syz.2.123/7345:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.170/7917:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.170/7919:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.170/7920:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.170/7928:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.170/7929:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.170/7930:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.170/7931:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.170/7932:
 #0: ffff88811bc360e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
4 locks held by syz-executor/8938:
7 locks held by syz-executor/10401:
 #0: ffff8881070e0420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
 #1: ffff8881127cb888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540
 #2: ffff8881084ef0f8 (kn->active#48){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540
 #3: ffffffff8efbc4a8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360
 #4: ffff888029d470e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800
 #5: ffff888029d46250 (&devlink->lock_key#16){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160
 #6: ffffffff8e342c80 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
3 locks held by dhcpcd-run-hook/10842:

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

NMI backtrace for cpu 0
CPU: 0 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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 10842 Comm: dhcpcd-run-hook 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:unwind_next_frame+0x22/0x2390
Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 81 ec 98 00 00 00 49 89 fe 48 bd 00 00 00 00 00 fc ff df <48> 8d 5f 48 48 89 d8 48 c1 e8 03 48 89 44 24 30 80 3c 28 00 74 08
RSP: 0018:ffffc90004e9f238 EFLAGS: 00000292
RAX: 0000000000000001 RBX: ffffc90004e9f3c0 RCX: 4ecf831e39163200
RDX: dffffc0000000000 RSI: ffffffff8225f48d RDI: ffffc90004e9f308
RBP: dffffc0000000000 R08: ffffc90004e9f3d0 R09: 0000000000000001
R10: ffffc90004e9f358 R11: ffffffff81acd510 R12: ffff8880115dba00
R13: 1ffff920009d3ee4 R14: ffffc90004e9f308 R15: ffffc90004e9f308
FS:  0000000000000000(0000) GS:ffff8881a39fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055db6bfa7a18 CR3: 000000000e138000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 kmem_cache_free+0x4b5/0x690
 __put_anon_vma+0x12b/0x2d0
 unlink_anon_vmas+0x503/0x670
 free_pgtables+0x72b/0x9c0
 exit_mmap+0x43c/0xb40
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3f7d966a90
Code: Unable to access opcode bytes at 0x7f3f7d966a66.
RSP: 002b:00007ffd2685ca98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055db6bf91910 RCX: 00007f3f7d966a90
RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00007ffd2685cdc8 R08: 000055db6bf91c58 R09: 843880b75bc20600
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd2685cdc0
R13: 00007ffd2685cdd0 R14: 000055db5ba9e169 R15: 00007f3f7db65a80
 </TASK>
