INFO: task kworker/u4:5:4217 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:5    state:D stack:    0 pid: 4217 ppid:     2 flags:0x00000008
Workqueue: events_unbound quota_release_workfn
Call trace:
 __switch_to+0x2f4/0x540 arch/arm64/kernel/process.c:521
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0xdfc/0x1bc4 kernel/sched/core.c:6395
 schedule+0x11c/0x1c8 kernel/sched/core.c:6478
 schedule_timeout+0xc8/0x2f4 kernel/time/timer.c:2093
 do_wait_for_common+0x204/0x374 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 __synchronize_srcu+0x270/0x308 kernel/rcu/srcutree.c:930
 synchronize_srcu+0x194/0x1ac kernel/rcu/srcutree.c:-1
 quota_release_workfn+0x104/0x624 fs/quota/dquot.c:828
 process_one_work+0x79c/0x1138 kernel/workqueue.c:2310
 worker_thread+0x8f4/0x1034 kernel/workqueue.c:2457
 kthread+0x374/0x454 kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:856
INFO: task syz.0.15:4932 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.15        state:D stack:    0 pid: 4932 ppid:  4738 flags:0x00000001
Call trace:
 __switch_to+0x2f4/0x540 arch/arm64/kernel/process.c:521
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0xdfc/0x1bc4 kernel/sched/core.c:6395
 schedule+0x11c/0x1c8 kernel/sched/core.c:6478
 io_schedule+0x84/0x160 kernel/sched/core.c:8503
 bit_wait_io+0x1c/0xac kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xb4/0x1e8 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x12c/0x180 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer+0x80/0xb8 fs/buffer.c:69
 lock_buffer include/linux/buffer_head.h:402 [inline]
 ext4_quota_write+0x330/0x544 fs/ext4/super.c:6638
 qtree_write_dquot+0x1a8/0x3f8 fs/quota/quota_tree.c:422
 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:358
 dquot_commit+0x128/0x1c4 fs/quota/dquot.c:514
 ext4_write_dquot+0x1b4/0x31c fs/ext4/super.c:6212
 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6289
 mark_dquot_dirty fs/quota/dquot.c:372 [inline]
 mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:412
 dquot_alloc_inode+0x680/0xbec fs/quota/dquot.c:1801
 ext4_xattr_inode_alloc_quota fs/ext4/xattr.c:866 [inline]
 ext4_xattr_set_entry+0x80c/0x2e50 fs/ext4/xattr.c:1669
 ext4_xattr_block_set+0x9a0/0x267c fs/ext4/xattr.c:1924
 ext4_xattr_set_handle+0xa60/0x10fc fs/ext4/xattr.c:2407
 ext4_xattr_set+0x1f4/0x2c0 fs/ext4/xattr.c:2508
 ext4_xattr_user_set+0xd4/0xfc fs/ext4/xattr_user.c:41
 __vfs_setxattr+0x384/0x3a0 fs/xattr.c:182
 __vfs_setxattr_noperm+0x120/0x564 fs/xattr.c:216
 __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:277
 vfs_setxattr+0x158/0x2ac fs/xattr.c:303
 do_setxattr fs/xattr.c:588 [inline]
 setxattr+0x278/0x2f8 fs/xattr.c:611
 path_setxattr+0x130/0x260 fs/xattr.c:630
 __do_sys_setxattr fs/xattr.c:646 [inline]
 __se_sys_setxattr fs/xattr.c:642 [inline]
 __arm64_sys_setxattr+0xbc/0xd8 fs/xattr.c:642
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1d0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014471360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:312
1 lock held by udevd/3659:
2 locks held by getty/3802:
 #0: ffff0000d4dab098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001be8b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2f0/0xf6c drivers/tty/n_tty.c:2158
2 locks held by kworker/u4:5/4217:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: ffff8000200d7c00 ((quota_release_work).work){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
6 locks held by syz.0.15/4932:
 #0: ffff0000d9458460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:386
 #1: ffff0000e58da1d8 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff0000e58da1d8 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_setxattr+0x138/0x2ac fs/xattr.c:302
 #2: ffff0000e58d9eb0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline]
 #2: ffff0000e58d9eb0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x134/0x10fc fs/ext4/xattr.c:2322
 #3: ffff8000145873f8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:312
 #4: ffff0000e58160a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x50/0x1c4 fs/quota/dquot.c:507
 #5: ffff0000d9458208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x80/0x180 fs/quota/quota_v2.c:356
4 locks held by syz-executor/21636:

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