INFO: task syz.5.4528:23187 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc7-syzkaller-00152-gd0c22de9995b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.4528      state:D stack:27576 pid:23187 tgid:23186 ppid:16415  task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084
 __down_read_common kernel/locking/rwsem.c:1248 [inline]
 __down_read kernel/locking/rwsem.c:1261 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526
 __super_lock fs/super.c:58 [inline]
 super_lock+0x2a9/0x3b0 fs/super.c:120
 super_lock_shared fs/super.c:139 [inline]
 iterate_supers+0x80/0x180 fs/super.c:931
 quota_sync_all fs/quota/quota.c:69 [inline]
 __do_sys_quotactl fs/quota/quota.c:938 [inline]
 __se_sys_quotactl+0x353/0x950 fs/quota/quota.c:917
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9e72b8e969
RSP: 002b:00007f9e739ac038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f9e72db5fa0 RCX: 00007f9e72b8e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102
RBP: 00007f9e72c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9e72db5fa0 R15: 00007ffd9dfc3788
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
2 locks held by getty/5584:
 #0: ffff8880309330a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/12217:
 #0: ffff88805dcc60e0 (&type->s_umount_key#92){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88805dcc60e0 (&type->s_umount_key#92){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88805dcc60e0 (&type->s_umount_key#92){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
1 lock held by syz.5.4528/23187:
 #0: ffff88805dcc60e0 (&type->s_umount_key#92){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88805dcc60e0 (&type->s_umount_key#92){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00152-gd0c22de9995b #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:437
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc7-syzkaller-00152-gd0c22de9995b #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:error_return+0x1/0x20 arch/x86/entry/entry_64.S:1091
Code: 30 90 e8 32 e5 ff ff eb 0c cc cc cc cc cc cc cc cc cc cc cc cc 48 8d 7c 24 08 e8 da 43 56 0a 48 89 c7 e9 92 43 56 0a 90 90 50 <9c> 58 a9 00 02 00 00 74 02 0f 0b 58 f6 84 24 88 00 00 00 03 0f 84
RSP: 0018:ffffffff8dc07cd0 EFLAGS: 00000086
RAX: e272cf6cb2f0d400 RBX: 0000000000000000 RCX: e272cf6cb2f0d400
RDX: 0000000000000001 RSI: ffffffff8d74e2e2 RDI: ffffffff8bc1f600
RBP: 0000000000000000 R08: ffff8880b8832b5b R09: 1ffff1101710656b
R10: dffffc0000000000 R11: ffffed101710656c R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881260c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e7d77fab8 CR3: 0000000030b06000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
Code: ee ad b9 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d a3 7f 11 00 f3 0f 1e fa fb f4 <e9> c3 ad b9 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 00000286
RAX: e272cf6cb2f0d400 RBX: ffffffff81977108 RCX: e272cf6cb2f0d400
RDX: 0000000000000001 RSI: ffffffff8d74e2e2 RDI: ffffffff8bc1f600
RBP: ffffffff8dc07ec0 R08: ffff8880b8832b5b R09: 1ffff1101710656b
R10: dffffc0000000000 R11: ffffed101710656c R12: ffffffff8f7f3570
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a48
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 rest_init+0x2de/0x300 init/main.c:743
 start_kernel+0x470/0x4f0 init/main.c:1099
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513
 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
 common_startup_64+0x13e/0x147
 </TASK>