INFO: task syz-executor:21258 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc7-syzkaller-00082-g5cdb2c77c4c3 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22232 pid:21258 tgid:21258 ppid:1      task_flags:0x400140 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
 io_schedule+0x81/0xe0 kernel/sched/core.c:7742
 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
 __folio_lock mm/filemap.c:1664 [inline]
 folio_lock include/linux/pagemap.h:1137 [inline]
 __filemap_get_folio+0x139/0xaf0 mm/filemap.c:1917
 truncate_inode_pages_range+0x3ed/0xda0 mm/truncate.c:384
 evict+0x517/0x9c0 fs/inode.c:812
 dispose_list fs/inode.c:852 [inline]
 evict_inodes+0x636/0x6c0 fs/inode.c:906
 generic_shutdown_super+0x9a/0x2c0 fs/super.c:627
 kill_block_super+0x44/0x90 fs/super.c:1710
 deactivate_locked_super+0xbc/0x130 fs/super.c:473
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1431
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218
 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c4518fc97
RSP: 002b:00007ffd9bfb4258 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f5c4521089d RCX: 00007f5c4518fc97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd9bfb4310
RBP: 00007ffd9bfb4310 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd9bfb53a0
R13: 00007f5c4521089d R14: 00000000000bc638 R15: 00007ffd9bfb53e0
 </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/5587:
 #0: ffff8880343520a0 (&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/21258:
 #0: ffff888047df80e0 (&type->s_umount_key#120){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888047df80e0 (&type->s_umount_key#120){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888047df80e0 (&type->s_umount_key#120){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
1 lock held by syz-executor/25573:
1 lock held by syz.0.10176/1081:
 #0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
 #0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
3 locks held by udevadm/1118:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00082-g5cdb2c77c4c3 #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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 81 Comm: kworker/u8:5 Not tainted 6.15.0-rc7-syzkaller-00082-g5cdb2c77c4c3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:__rcu_read_unlock+0x0/0xe0 kernel/rcu/tree_plugin.h:431
Code: 89 d9 80 e1 07 80 c1 03 38 c1 7c dc 48 89 df e8 96 1e 7a 00 eb d2 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 41 57 41 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff
RSP: 0018:ffffc9000240f938 EFLAGS: 00000282
RAX: 889d5daea892ba00 RBX: 00000000000001b4 RCX: 889d5daea892ba00
RDX: 0000000000000003 RSI: ffffffff8d938bac RDI: ffffffff8bc1f3c0
RBP: ffffc9000240fa70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8b1f6568 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff888057c850b4
FS:  0000000000000000(0000) GS:ffff8881261c2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f05a25f7e9c CR3: 0000000031e7a000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 rcu_read_unlock include/linux/rcupdate.h:873 [inline]
 batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:779 [inline]
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline]
 batadv_iv_ogm_schedule+0x6d6/0xea0 net/batman-adv/bat_iv_ogm.c:876
 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1720
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 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>