INFO: task syz.1.2164:15965 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2164      state:D stack:25040 pid:15965 ppid:  4185 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 rwsem_down_read_slowpath+0x548/0x9d0 kernel/locking/rwsem.c:1055
 __down_read_common kernel/locking/rwsem.c:1239 [inline]
 __down_read kernel/locking/rwsem.c:1252 [inline]
 down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
 iterate_supers+0xa4/0x1d0 fs/super.c:716
 quota_sync_all fs/quota/quota.c:68 [inline]
 __do_sys_quotactl fs/quota/quota.c:936 [inline]
 __se_sys_quotactl+0x33b/0x6f0 fs/quota/quota.c:915
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2326092799
RSP: 002b:00007f23242ec028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f232630bfa0 RCX: 00007f2326092799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102
RBP: 00007f2326128bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f232630c038 R14: 00007f232630bfa0 R15: 00007ffdd7e91758
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
5 locks held by kworker/0:1/13:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/0:1H/1290:
2 locks held by getty/3950:
 #0: ffff88814ccba098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
4 locks held by udevd/4175:
 #0: ffff88807b4088b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182
 #1: ffff888062d36088 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112
 #2: ffff88805cc44748 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113
 #3: ffff88806087b220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #3: ffff88806087b220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408
2 locks held by kworker/u4:6/4255:
1 lock held by syz-executor/6620:
 #0: ffff88807db500e0 (&type->s_umount_key#88){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
5 locks held by kworker/1:11/7579:
 #0: ffff888141dc6938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900033ffd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff888148490220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #2: ffff888148490220 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x55e0 drivers/usb/core/hub.c:5827
 #3: ffff88806087b220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #3: ffff88806087b220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:954
 #4: ffff88807df141a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #4: ffff88807df141a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:954
1 lock held by syz.1.2164/15965:
 #0: ffff88807db500e0 (&type->s_umount_key#88){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.2.2690/20270:
 #0: ffff88807db500e0 (&type->s_umount_key#88){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
2 locks held by kworker/1:0/21064:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc90004af7d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
2 locks held by kworker/1:1/22658:
1 lock held by syz.6.2961/22871:
 #0: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.3.2965/22910:
 #0: ffffffff8c323430 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043
1 lock held by sed/22993:

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 22901 Comm: syz.4.2964 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:put_prev_task_rt+0x267/0x3a0 kernel/sched/rt.c:1684
Code: 09 00 00 49 89 de 49 c1 ee 03 43 0f b6 04 2e 84 c0 0f 85 03 01 00 00 3b 2b 7d 0f 43 0f b6 04 2e 84 c0 0f 85 0f 01 00 00 89 2b <48> 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b e9 21 fe ff ff
RSP: 0018:ffffc90002f5f758 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880b903a340 RCX: 51a88106db2ccc00
RDX: 0000000000000001 RSI: ffff8880b903a340 RDI: ffff8880b903ae90
RBP: ffffc90002f5f980 R08: ffff88814077b007 R09: 1ffff110280ef600
R10: dffffc0000000000 R11: ffffed10280ef601 R12: ffff888063b10080
R13: dffffc0000000000 R14: ffff888063b10000 R15: ffff888063b101e4
FS:  00007f14a5b3b6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000009000 CR3: 00000000315db000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 put_prev_task kernel/sched/sched.h:2190 [inline]
 put_prev_task_balance kernel/sched/core.c:5648 [inline]
 pick_next_task kernel/sched/core.c:5816 [inline]
 __schedule+0x22fa/0x43c0 kernel/sched/core.c:6359
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 snd_rawmidi_write+0x3b6/0xc10 sound/core/rawmidi.c:1542
 do_loop_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x3e4/0x7b0 fs/read_write.c:857
 vfs_writev fs/read_write.c:928 [inline]
 do_writev+0x281/0x480 fs/read_write.c:971
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f14a78e1799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f14a5b3b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f14a7b5afa0 RCX: 00007f14a78e1799
RDX: 0000000000000002 RSI: 0000200000000840 RDI: 0000000000000008
RBP: 00007f14a7977bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f14a7b5b038 R14: 00007f14a7b5afa0 R15: 00007ffe65acbb58
 </TASK>