INFO: task syz.0.665:6094 blocked for more than 143 seconds.
      Not tainted 5.15.168-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.665       state:D stack:24024 pid: 6094 ppid:  3569 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6515
 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 exfat_sync_fs+0x67/0x100 fs/exfat/super.c:64
 iterate_supers+0x127/0x1e0 fs/super.c:718
 ksys_sync+0xd7/0x1c0 fs/sync.c:104
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f86e2876ff9
RSP: 002b:00007f86e0cef038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f86e2a2ef80 RCX: 00007f86e2876ff9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f86e28e9296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f86e2a2ef80 R15: 00007fff34d58908
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fc20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:2/154:
 #0: ffff888017079138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90002017d20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
2 locks held by udevd/3029:
 #0: ffff8880211bc518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
 #1: ffff888147463468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x68/0x100 drivers/block/loop.c:2055
2 locks held by getty/3332:
 #0: ffff88802a1a3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc9000208e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by syz-executor/3571:
2 locks held by kworker/u4:6/3658:
 #0: ffff888017079138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003157d20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
2 locks held by kworker/1:14/4464:
 #0: ffff8880b913a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffff8880b9127848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x53d/0x810 kernel/sched/psi.c:891
3 locks held by kworker/1:15/4465:
 #0: ffff888017070938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003967d20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8c9241e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #2: ffffffff8c9241e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
1 lock held by syz-executor/5533:
 #0: ffff888147463468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365
2 locks held by syz.0.665/6094:
 #0: ffff888076d200e0 (&type->s_umount_key#99){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:716
 #1: ffff88805dde80e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_sync_fs+0x67/0x100 fs/exfat/super.c:64
2 locks held by syz.3.928/6845:
 #0: ffff888076d200e0 (&type->s_umount_key#99){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:716
 #1: ffff88805dde80e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_sync_fs+0x67/0x100 fs/exfat/super.c:64
2 locks held by syz.1.1920/9323:
 #0: ffff8880211ab118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
 #1: ffff88802148a468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2070

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.168-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 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:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3658 Comm: kworker/u4:6 Not tainted 5.15.168-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_preemption_disabled+0x19/0x110 lib/smp_processor_id.c:14
Code: cc 48 c7 c7 20 02 d9 8a 48 c7 c6 60 02 d9 8a eb 00 41 57 41 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 1d b8 b2 cd 75 65 8b 05 21 0d ce 75 a9 ff ff ff 7f 74 22 65
RSP: 0018:ffffc90003157a28 EFLAGS: 00000286
RAX: fb00c696fcfe5300 RBX: 0000000000000001 RCX: ffffffff8162bd8c
RDX: 0000000000000000 RSI: ffffffff8ad90260 RDI: ffffffff8ad90220
RBP: ffffc90003157bd8 R08: dffffc0000000000 R09: fffffbfff1bd2cbe
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200062af58
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888062ed4f80
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f63dae19a8c CR3: 00000000790fc000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
 rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:1123
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0xdd/0x4f0 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [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:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>