INFO: task syz-executor.2:14766 blocked for more than 143 seconds.
      Not tainted 5.15.139-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:25464 pid:14766 ppid:  8018 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 rwsem_down_read_slowpath+0x605/0xb40 kernel/locking/rwsem.c:1047
 __down_read_common kernel/locking/rwsem.c:1231 [inline]
 __down_read kernel/locking/rwsem.c:1244 [inline]
 down_read+0x9a/0x2e0 kernel/locking/rwsem.c:1490
 iterate_supers+0xac/0x1e0 fs/super.c:703
 ksys_sync+0xb9/0x1c0 fs/sync.c:102
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fd2cb377ae9
RSP: 002b:00007fd2c98b70c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd2cb497120 RCX: 00007fd2cb377ae9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd2cb3c347a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fd2cb497120 R15: 00007ffff4dda848
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91f060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3259:
 #0: ffff88814b650098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
1 lock held by syz-executor.5/12967:
 #0: ffff8880769600e0 (&type->s_umount_key#75/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229
1 lock held by syz-executor.2/14766:
 #0: ffff8880769600e0 (&type->s_umount_key#76){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.5/14821:
 #0: ffff8880769600e0 (&type->s_umount_key#76){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.2/14839:
 #0: ffff8880769600e0 (&type->s_umount_key#76){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.1/14856:
 #0: ffff8880769600e0 (&type->s_umount_key#76){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.3/14861:
 #0: ffff8880769600e0 (&type->s_umount_key#76){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.5/14908:
 #0: ffff8880769600e0 (&type->s_umount_key#76){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.2/14914:
 #0: ffff8880769600e0 (&type->s_umount_key#76){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.139-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15319 Comm: kworker/u4:8 Not tainted 5.15.139-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0xcba/0x1ff0 kernel/locking/lockdep.c:4981
Code: 00 00 e8 39 5a 00 00 31 f6 85 c0 0f 84 a6 08 00 00 48 c7 c0 00 60 3c 91 48 c1 e8 03 48 bf 00 00 00 00 00 fc ff df 0f b6 04 38 <84> c0 0f 85 0e 0c 00 00 83 3d 47 cf d9 0f 00 75 44 48 8b 6c 24 58
RSP: 0018:ffffc9000539f9a0 EFLAGS: 00000806
RAX: 0000000000000004 RBX: ffff88801ec546c0 RCX: ffffffff8162eb58
RDX: 0000000000000000 RSI: 0000000000000000 RDI: dffffc0000000000
RBP: ffff88801ec53b80 R08: dffffc0000000000 R09: fffffbfff1f79c21
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000002
R13: ffff88801ec54668 R14: 0000000000000002 R15: ffff88801ec546e0
FS:  0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c005a7e000 CR3: 000000007a78c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:269
 rcu_read_lock include/linux/rcupdate.h:696 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xc1/0x5b0 net/batman-adv/network-coding.c:723
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>