INFO: task syz.0.17:6439 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:27528 pid:6439  tgid:6437  ppid:6361   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4c90 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 super_lock+0x1c8/0x3a0 fs/super.c:115
 __iterate_supers+0x124/0x620 fs/super.c:923
 ksys_sync+0x94/0x150 fs/sync.c:102
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2cf2f8ebe9
RSP: 002b:00007f2cf3e3e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f2cf31c6090 RCX: 00007f2cf2f8ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f2cf31c6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2cf31c6128 R14: 00007f2cf31c6090 R15: 00007ffe89769928
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8dd3a160 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8dd3a160 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8dd3a160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:4/59:
2 locks held by getty/5572:
 #0: ffff8880332850a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz.0.17/6438:
 #0: ffff8880293900e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
1 lock held by syz.2.19/6486:
 #0: ffff88806c9bc0e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
1 lock held by syz.3.20/6516:
 #0: ffff8880277ae0e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
1 lock held by syz.4.21/6545:
 #0: ffff88807ad3c0e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
1 lock held by syz.5.22/6576:
 #0: ffff88805ba980e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
1 lock held by syz.6.23/6610:
 #0: ffff88805651e0e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
1 lock held by syz.7.24/6642:
 #0: ffff88805705a0e0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0x15af/0x15f0 kernel/hung_task.c:491
 kthread+0x70e/0x890 kernel/kthread.c:463
 ret_from_fork+0x435/0x7c0 arch/x86/kernel/process.c:148
 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: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x39/0x350 kernel/locking/lockdep.c:5831
Code: 83 ec 60 4d 89 ce 45 89 c7 41 89 cc 89 54 24 04 89 f3 49 89 fd 48 8b ac 24 98 00 00 00 65 48 8b 05 5c 7f a4 10 48 89 44 24 58 <0f> 1f 44 00 00 65 8b 05 5f 7f a4 10 83 f8 08 0f 83 b8 01 00 00 89
RSP: 0018:ffffc90000117960 EFLAGS: 00000286
RAX: d408eb1d3c904200 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8dd3a160
RBP: ffffffff8af40e02 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8af40d30 R12: 0000000000000002
R13: ffffffff8dd3a160 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888126411000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559a8f267690 CR3: 000000000db36000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xade/0x1790 kernel/workqueue.c:3319
 worker_thread+0xa57/0xfc0 kernel/workqueue.c:3400
 kthread+0x70e/0x890 kernel/kthread.c:463
 ret_from_fork+0x435/0x7c0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>