INFO: task syz.2.353:7755 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.353       state:D stack:25000 pid:7755  tgid:7754  ppid:5620   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6d9/0x940
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x250
 __se_sys_quotactl+0x3a7/0x9e0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0f1779cdd9
RSP: 002b:00007f0f186e2028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f0f17a15fa0 RCX: 00007f0f1779cdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100
RBP: 00007f0f17832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0f17a16038 R14: 00007f0f17a15fa0 R15: 00007fff02304598
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5438:
 #0: ffff888100f500a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
2 locks held by syz-executor/5612:
3 locks held by kworker/0:4/5675:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc9000483fc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff88810c384250 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
1 lock held by syz.2.353/7755:
 #0: ffff8881205320d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.8.582/9205:
 #0: ffff8881205320d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.8.582/9206:
 #0: ffff8881205320d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.8.582/9207:
 #0: ffff8881205320d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/10054:
 #0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz.1.813/10753:
 #0: ffff8881205320d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by dhcpcd-run-hook/11077:

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 11061 Comm: syz.3.848 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:shmem_get_folio_gfp+0x5a9/0x1670
Code: ff 48 8b 6c 24 38 4c 8b 7c 24 20 48 8b bc 24 e0 00 00 00 8b 74 24 10 48 8b 54 24 18 4c 89 f1 4d 89 f8 45 31 c9 e8 87 72 00 00 <48> 89 84 24 98 00 00 00 48 3d 00 f0 ff ff 0f 86 f5 05 00 00 49 89
RSP: 0018:ffffc90004f7f9e0 EFLAGS: 00000246
RAX: ffffea0006a0b740 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc90024732000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffff888106bdaba8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff3494288 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000743 R15: 0000000000000000
FS:  00007f0a939f66c0(0000) GS:ffff8882a928d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fc5a3d8950 CR3: 000000011f958000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 shmem_write_begin+0x16c/0x330
 generic_perform_write+0x2e2/0x8f0
 shmem_file_write_iter+0xf8/0x120
 vfs_write+0x61d/0xb90
 ksys_write+0x150/0x270
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a9575d60e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f0a939f5da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0a939f66c0 RCX: 00007f0a9575d60e
RDX: 00000000013bd7ef RSI: 00007f0a8b400000 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 00007f0a939f5ee0 R14: 00007f0a939f5ea0 R15: 00007f0a8b400000
 </TASK>
