INFO: task syz.2.338:7175 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc6-next-20241108-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.338       state:D stack:23448 pid:7175  tgid:7174  ppid:5830   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x1850/0x4c30 kernel/sched/core.c:6753
 __schedule_loop kernel/sched/core.c:6830 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6845
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6902
 __mutex_lock_common kernel/locking/mutex.c:665 [inline]
 __mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735
 exfat_sync_fs+0xb0/0x160 fs/exfat/super.c:56
 iterate_supers+0xc6/0x190 fs/super.c:934
 ksys_sync+0xdb/0x1c0 fs/sync.c:104
 __do_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb25d57e719
RSP: 002b:00007fb25e3d1038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fb25d735f80 RCX: 00007fb25d57e719
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb25d5f139e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb25d735f80 R15: 00007ffe6b03b148
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e93c560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e93c560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e93c560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744
2 locks held by getty/5581:
 #0: ffff88814c8120a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000324b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
3 locks held by syz-executor/5825:
3 locks held by kworker/1:6/5883:
 #0: ffff8880226a6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff8880226a6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900041ffd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900041ffd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff888144be4190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline]
 #2: ffff888144be4190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849
2 locks held by syz.2.338/7175:
 #0: ffff8880242b80e0 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880242b80e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff8880217500e8 (&sbi->s_lock#2){+.+.}-{4:4}, at: exfat_sync_fs+0xb0/0x160 fs/exfat/super.c:56
2 locks held by kworker/u8:10/7760:
3 locks held by syz.0.772/8794:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-next-20241108-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline]
 watchdog+0xffb/0x1040 kernel/hung_task.c:397
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc6-next-20241108-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:__memcg_slab_free_hook+0x187/0x310 mm/memcontrol.c:3028
Code: 0f b6 c6 83 f8 20 0f 83 68 01 00 00 44 89 f1 d3 ed 89 e9 89 c8 48 8b 4c 24 40 48 8d 2c c1 48 89 eb 48 c1 eb 03 42 80 3c 3b 00 <74> 08 48 89 ef e8 3f dc f6 ff 4c 8b 75 00 4d 85 f6 0f 84 09 ff ff
RSP: 0018:ffffc90000157940 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 1ffff1100efd83eb RCX: ffff888077ec1f40
RDX: 0000777fd56a8000 RSI: ffffea0000aa5600 RDI: ffffc900001579d0
RBP: ffff888077ec1f58 R08: ffff888077ec1f40 R09: 1ffffffff203910e
R10: dffffc0000000000 R11: fffffbfff203910f R12: 0000000000000c01
R13: 0000000000000000 R14: 000000000000000c R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c26baf9 CR3: 0000000024c1e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 memcg_slab_free_hook mm/slub.c:2178 [inline]
 slab_free mm/slub.c:4595 [inline]
 kmem_cache_free+0x222/0x410 mm/slub.c:4700
 put_task_struct include/linux/sched/task.h:144 [inline]
 delayed_put_task_struct+0x125/0x300 kernel/exit.c:227
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 run_ksoftirqd+0xca/0x130 kernel/softirq.c:943
 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>