INFO: task syz.0.18:4890 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.18        state:D stack:25472 pid: 4890 ppid:  4728 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093
 do_wait_for_common+0x295/0x460 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 kthread_stop+0x16e/0x540 kernel/kthread.c:666
 ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:263
 ext4_fill_super+0x63ae/0x93f0 fs/ext4/super.c:5117
 mount_bdev+0x28a/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x247/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 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: 0033:0x7fd34b19ab8a
RSP: 002b:00007fd34a3ffe58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd34a3ffee0 RCX: 00007fd34b19ab8a
RDX: 0000400000000040 RSI: 0000400000000000 RDI: 00007fd34a3ffea0
RBP: 0000400000000040 R08: 00007fd34a3ffee0 R09: 0000000003010008
R10: 0000000003010008 R11: 0000000000000246 R12: 0000400000000000
R13: 00007fd34a3ffea0 R14: 0000000000000538 R15: 0000400000000340
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u4:1/144:
 #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
 #1: ffffc9000114fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff8880b90280d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:946
2 locks held by getty/3946:
 #0: ffff88802be67098 (&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+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by syz.0.18/4890:
 #0: ffff88807590c0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
1 lock held by syz.1.20/4913:
 #0: ffff888070faa0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
1 lock held by syz.2.22/4933:
 #0: ffff88807e44c0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
1 lock held by syz.3.24/4953:
 #0: ffff88807f1b60e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
1 lock held by syz.4.27/4989:
 #0: ffff888067ee20e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
1 lock held by syz.5.30/5018:
 #0: ffff88801d0d20e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
1 lock held by syz.6.31/5040:
 #0: ffff88807f2980e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
1 lock held by syz.7.32/5063:
 #0: ffff8880562fa0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
1 lock held by syz.8.39/5109:
 #0: ffff88807eb560e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229

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

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 07/24/2026
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+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/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: 144 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_bla_periodic_work
RIP: 0010:check_region_inline mm/kasan/generic.c:-1 [inline]
RIP: 0010:kasan_check_range+0x33/0x290 mm/kasan/generic.c:189
Code: 00 00 55 41 57 41 56 41 54 53 49 89 f8 49 01 f0 0f 82 0e 02 00 00 49 89 f8 49 c1 e8 2f 41 81 f8 ff ff 01 00 0f 82 fa 01 00 00 <49> bc 01 00 00 00 00 fc ff df 49 89 fe 49 c1 ee 03 49 ba 00 00 00
RSP: 0018:ffffc9000114f650 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000015 RCX: ffffffff815ceda7
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901ee0c0
RBP: ffffc9000114f8b0 R08: 000000000001ffff R09: 1ffffffff203dc18
R10: dffffc0000000000 R11: fffffbfff203dc19 R12: ffff8880189d8b60
R13: ffff8880189d8000 R14: 0000000000000002 R15: ffff8880189d8b40
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005608e7323a38 CR3: 000000007eae5000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 __lock_acquire+0xdd7/0x7b50 kernel/locking/lockdep.c:4982
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 batadv_bla_purge_claims+0x149/0x870 net/batman-adv/bridge_loop_avoidance.c:1319
 batadv_bla_periodic_work+0xb2/0xaa0 net/batman-adv/bridge_loop_avoidance.c:1482
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>