INFO: task syz.0.26:5372 blocked for more than 143 seconds.
      Not tainted 5.15.186-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.26        state:D stack:26240 pid: 5372 ppid:  5349 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 rwsem_down_write_slowpath+0xc46/0x11f0 kernel/locking/rwsem.c:1165
 user_get_super+0xcd/0x240 fs/super.c:848
 quotactl_block fs/quota/quota.c:889 [inline]
 __do_sys_quotactl fs/quota/quota.c:953 [inline]
 __se_sys_quotactl+0x45e/0x6c0 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: 0033:0x7f42524cb929
RSP: 002b:00007f425173b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f42526f2fa0 RCX: 00007f42524cb929
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: ffffffff80000302
RBP: 00007f425254db39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f42526f2fa0 R15: 00007ffe9a5d1ab8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3948:
 #0: ffff88802bbcf098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
3 locks held by syz.0.16/5076:
3 locks held by syz.1.17/5101:
3 locks held by syz.2.18/5123:
3 locks held by syz.3.19/5148:
3 locks held by syz.4.20/5182:
3 locks held by syz.5.21/5211:
3 locks held by syz.6.22/5243:
3 locks held by syz.7.23/5278:
3 locks held by syz.8.24/5308:
3 locks held by syz.9.25/5346:
1 lock held by syz.0.26/5372:
 #0: ffff888076f2e0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: user_get_super+0xcd/0x240 fs/super.c:848
1 lock held by syz.1.27/5398:
 #0: ffff888078ca80e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: user_get_super+0xcd/0x240 fs/super.c:848
1 lock held by syz.2.28/5426:
 #0: ffff8880267ac0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: user_get_super+0xcd/0x240 fs/super.c:848
1 lock held by syz.3.29/5451:
 #0: ffff88807a1440e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: user_get_super+0xcd/0x240 fs/super.c:848
1 lock held by syz.4.30/5488:
 #0: ffff888058c260e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: user_get_super+0xcd/0x240 fs/super.c:848
1 lock held by syz-executor308/5498:
 #0: ffff888076f2e0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: user_get_super+0xcd/0x240 fs/super.c:848
1 lock held by syz.5.31/5527:
 #0: ffff8880782360e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: user_get_super+0xcd/0x240 fs/super.c:848

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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: 754 Comm: kworker/u4:3 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:mark_lock+0xf6/0x320 kernel/locking/lockdep.c:4610
Code: 00 74 36 45 31 ff 49 83 c7 50 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 04 9f 60 00 b8 01 00 00 00 45 85 27 74 50 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 96 c3 7b 02 85 c0
RSP: 0018:ffffc90003f4f980 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff88801f905940 RCX: ffffffff815c9cb4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffba1c0
RBP: 0000000000000002 R08: dffffc0000000000 R09: fffffbfff1ff7439
R10: fffffbfff1ff7439 R11: 1ffffffff1ff7438 R12: 0000000000000004
R13: dffffc0000000000 R14: ffff88801f906430 R15: ffffffff8f9a3dd0
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055cf93516168 CR3: 000000007d3ec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mark_held_locks kernel/locking/lockdep.c:4193 [inline]
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4211 [inline]
 lockdep_hardirqs_on_prepare+0x23c/0x760 kernel/locking/lockdep.c:4278
 trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49
 __local_bh_enable_ip+0x12a/0x1b0 kernel/softirq.c:406
 spin_unlock_bh include/linux/spinlock.h:408 [inline]
 batadv_nc_purge_paths+0x316/0x3b0 net/batman-adv/network-coding.c:475
 batadv_nc_worker+0x327/0x5c0 net/batman-adv/network-coding.c:726
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>