INFO: task syz.3.756:9975 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.756       state:D stack:28136 pid:9975  tgid:9964  ppid:6968   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 vfs_setxattr+0x144/0x2f0
 filename_setxattr+0x274/0x600
 path_setxattrat+0x364/0x3a0
 __x64_sys_setxattr+0xbc/0xe0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff39db8ebe9
RSP: 002b:00007ff39bdf6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 00007ff39ddc6180 RCX: 00007ff39db8ebe9
RDX: 00002000000013c0 RSI: 0000200000000140 RDI: 0000200000000100
RBP: 00007ff39dc11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000700 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff39ddc6218 R14: 00007ff39ddc6180 R15: 00007ffd72f7c7d8
 </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
2 locks held by getty/5673:
 #0: ffff8880227910a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
5 locks held by kworker/0:4/5896:
 #0: ffff88801b3eed48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003d3fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88801f6c7198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff88801edc8198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff88801edcf160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
4 locks held by syz.3.756/9974:
 #0: ffff888121b5e428 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff8881127d2b30 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0
 #2: ffff888121b5e618 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc+0xd7/0x980
 #3: ffff8881127d2918 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_trans_alloc_inode+0x161/0x4a0
2 locks held by syz.3.756/9975:
 #0: ffff888121b5e428 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff8881127d2b30 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0
2 locks held by syz.9.1517/13282:

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

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: 13 Comm: kworker/u8:1 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
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_preemption_disabled+0x5c/0x120
Code: 9e 26 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 81 c9 02 00 cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 <f7> 04 24 00 02 00 00 74 c8 65 4c 8b 3c 25 08 80 a0 92 41 f6 47 2f
RSP: 0018:ffffc90000107948 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8dba76a9 RDI: ffffffff8be33900
RBP: ffffffff8b4754a2 R08: 0000000000000000 R09: ffffffff8b4754a2
R10: dffffc0000000000 R11: ffffffff8b4753d0 R12: 0000000000000002
R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2a785bd000 CR3: 000000004194c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x130/0x360
 batadv_nc_worker+0xef/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
