INFO: task syz.3.646:6754 blocked for more than 144 seconds.
      Not tainted 5.15.165-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.646       state:D stack:26648 pid: 6754 ppid:  5760 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:716
 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: 0033:0x7eff92a53ef9
RSP: 002b:00007eff90eaf038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007eff92bf0058 RCX: 00007eff92a53ef9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007eff92ac193e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007eff92bf0058 R15: 00007fff9e3369f8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/0:3/2988:
3 locks held by udevd/3027:
2 locks held by getty/3333:
 #0: ffff88814b51b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc9000249c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by syz-executor/3574:
2 locks held by kworker/u4:8/3981:
 #0: ffff888011c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900031d7d20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
3 locks held by syz-executor/4192:
1 lock held by syz.1.583/6482:
2 locks held by syz.3.646/6754:
 #0: ffff88805e74c0e0 (&type->s_umount_key#77){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:714
 #1: ffff88805e75e0e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_sync_fs+0x67/0x100 fs/exfat/super.c:64
1 lock held by syz-executor/6932:
4 locks held by kworker/u4:18/7848:
 #0: ffff888015192938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900039c7d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff88814b7340e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418
 #3: ffff88814b736bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1f6/0x3d10 fs/ext4/inode.c:2688
1 lock held by syz.1.1056/8720:
2 locks held by syz.1.1056/8721:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.165-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
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: 3574 Comm: syz-executor Not tainted 5.15.165-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:__this_cpu_preempt_check+0x0/0x10 lib/smp_processor_id.c:65
Code: 4c 89 fe 4c 89 f2 e8 af c0 fe ff 48 8b 74 24 30 48 c7 c7 40 f8 d8 8a e8 9e c0 fe ff e8 e9 6a ff ff eb a9 e8 22 eb ff ff 66 90 <48> 89 fe 48 c7 c7 c0 f7 d8 8a e9 e1 fe ff ff cc eb 1e 0f 1f 00 48
RSP: 0018:ffffc90002e27530 EFLAGS: 00000046
RAX: 0000000000000003 RBX: 0000000000000003 RCX: ffff88802194d940
RDX: 0000000000000000 RSI: ffffffff8c91fc40 RDI: ffffffff8a8b3cc0
RBP: 0000000000000000 R08: ffffffff81ac60ce R09: fffff940002d9e49
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000246
R13: ffff88802194d940 R14: 00000000ffffffff R15: ffffffff8c91fc40
FS:  00005555558ed500(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff0852bde8 CR3: 00000000649e1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
 lock_is_held_type+0xfd/0x180 kernel/locking/lockdep.c:5667
 lock_is_held include/linux/lockdep.h:287 [inline]
 ___might_sleep+0xa2/0x6a0 kernel/sched/core.c:9602
 __getblk_gfp+0x43/0xaf0 fs/buffer.c:1334
 __bread_gfp+0x2a/0x390 fs/buffer.c:1381
 sb_bread include/linux/buffer_head.h:337 [inline]
 __exfat_ent_get fs/exfat/fatent.c:47 [inline]
 exfat_ent_get+0x149/0x400 fs/exfat/fatent.c:96
 exfat_readdir fs/exfat/dir.c:184 [inline]
 exfat_iterate+0xda2/0x34a0 fs/exfat/dir.c:258
 iterate_dir+0x224/0x570
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0x209/0x4f0 fs/readdir.c:354
 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: 0033:0x7f32a4b6c093
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 32 43 f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8
RSP: 002b:00007fff948069d8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 0000555555908600 RCX: 00007f32a4b6c093
RDX: 0000000000008000 RSI: 0000555555908600 RDI: 0000000000000005
RBP: 00005555559085d4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000293 R12: ffffffffffffffa8
R13: 0000000000000010 R14: 00005555559085d0 R15: 00007fff94808c80
 </TASK>