INFO: task syz.6.2168:17802 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.2168      state:D stack:23152 pid:17802 ppid: 17173 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: 0033:0x7fc750763799
RSP: 002b:00007fc74e9bd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fc7509dcfa0 RCX: 00007fc750763799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007fc7507f9bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc7509dd038 R14: 00007fc7509dcfa0 R15: 00007ffe6b6551b8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by udevd/3562:
2 locks held by getty/3946:
 #0: ffff88814cfe9098 (&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
1 lock held by syz.0.1590/13319:
 #0: ffff8880615860e0 (&type->s_umount_key#125/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.6.2168/17802:
 #0: ffff8880615860e0 (&type->s_umount_key#128){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716

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

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: 4284 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__this_cpu_preempt_check+0x0/0x10 lib/smp_processor_id.c:65
Code: 48 89 da e8 02 48 f5 ff 48 8b 74 24 30 48 c7 c7 80 f8 79 8a e8 f1 47 f5 ff e8 1c 09 f8 ff eb a8 e8 d5 ee ff ff 0f 1f 44 00 00 <48> 89 fe 48 c7 c7 00 f8 79 8a e9 e1 fe ff ff 00 eb 1e 0f 1f 00 48
RSP: 0018:ffffc900032efab8 EFLAGS: 00000046
RAX: 1ffff110050b58cc RBX: 3d9d6e8e81309265 RCX: 0000000000000001
RDX: 0000000000000002 RSI: ffffffff8c31eaa0 RDI: ffffffff8a2b3a20
RBP: ffffc900032efbd0 R08: ffffffff8d89dc2f R09: 1ffffffff1b13b85
R10: dffffc0000000000 R11: fffffbfff1b13b86 R12: ffff8880285ac6c0
R13: dffffc0000000000 R14: ffff8880285ac660 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e604c13950 CR3: 000000002fd5a000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
 lock_release+0x549/0x8a0 kernel/locking/lockdep.c:5645
 rcu_read_unlock include/linux/rcupdate.h:773 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline]
 batadv_nc_worker+0x25b/0x5c0 net/batman-adv/network-coding.c:723
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>