INFO: task syz-executor:7250 blocked for more than 143 seconds.
      Tainted: G        W           syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21960 pid:7250  tgid:7250  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
 __writeback_inodes_sb_nr+0x1f7/0x270 fs/fs-writeback.c:2748
 sync_filesystem+0xa2/0x250 fs/sync.c:54
 generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618
 deactivate_locked_super+0xb9/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5953ceff17
RSP: 002b:00007ffd616578c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f5953d71c05 RCX: 00007f5953ceff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd61657980
RBP: 00007ffd61657980 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd61658a10
R13: 00007f5953d71c05 R14: 0000000000031994 R15: 00007ffd61658a50
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G        W           syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 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: 10180 Comm: kworker/u8:14 Tainted: G        W           syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:preempt_count_sub+0x51/0x170 kernel/sched/core.c:5858
Code: 83 3d 52 24 71 17 00 75 25 65 8b 05 39 f1 65 10 89 c1 81 e1 ff ff ff 7f 39 cf 7f 2a 81 ff ff 00 00 00 0f 93 c1 84 c0 0f 95 c0 <08> c8 74 5e 65 8b 05 14 f1 65 10 f7 df 65 01 3d 0b f1 65 10 5b 5d
RSP: 0018:ffffc90005cff668 EFLAGS: 00000002
RAX: 0000000080000001 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff88802f36bfc0 RSI: ffffffff8b620c60 RDI: 0000000000000001
RBP: ffffc90005cff770 R08: ffff8880b8923d3b R09: 1ffff110171247a7
R10: dffffc0000000000 R11: ffffed10171247a8 R12: dffffc0000000000
R13: 1ffff92000b9fed8 R14: ffffffff8d24ed18 R15: ffff88802f36bfa0
FS:  0000000000000000(0000) GS:ffff8881269c5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6b63d71d4 CR3: 00000000691bc000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 class_preempt_destructor include/linux/preempt.h:472 [inline]
 migrate_enable+0x29c/0x3c0 kernel/sched/core.c:2442
 __local_bh_enable+0x23f/0x3d0 kernel/softirq.c:214
 __local_bh_enable_ip+0x1a4/0x270 kernel/softirq.c:262
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 spin_unlock_bh include/linux/spinlock_rt.h:111 [inline]
 batadv_nc_purge_paths+0x34d/0x3f0 net/batman-adv/network-coding.c:471
 batadv_nc_worker+0x8c8/0xbc0 net/batman-adv/network-coding.c:722
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>