INFO: task kworker/u8:9:2862 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9    state:D stack:22136 pid:2862  tgid:2862  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1a0b/0x4be0 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd60 kernel/locking/mutex.c:752
 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105
 write_inode fs/fs-writeback.c:1498 [inline]
 __writeback_single_inode+0x6b9/0x1090 fs/fs-writeback.c:1715
 writeback_sb_inodes+0x905/0x1250 fs/fs-writeback.c:1941
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2012
 wb_writeback+0x46b/0xcc0 fs/fs-writeback.c:2119
 wb_check_background_flush fs/fs-writeback.c:2189 [inline]
 wb_do_writeback fs/fs-writeback.c:2277 [inline]
 wb_workfn+0xc92/0x10d0 fs/fs-writeback.c:2304
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0xa10/0x17b0 kernel/workqueue.c:3348
 worker_thread+0xa60/0xff0 kernel/workqueue.c:3429
 kthread+0x2f0/0x390 kernel/kthread.c:388
 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>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8dd302a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
4 locks held by kworker/u8:9/2862:
 #0: ffff8880166ed148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline]
 #0: ffff8880166ed148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17b0 kernel/workqueue.c:3348
 #1: ffffc9000a457d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline]
 #1: ffffc9000a457d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17b0 kernel/workqueue.c:3348
 #2: ffff88807ce4a0e0 (&type->s_umount_key#51){.+.+}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561
 #3: ffff88807ce480e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105
2 locks held by getty/4776:
 #0: ffff8880292350a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
4 locks held by syz-executor.0/5378:

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfd6/0x1020 kernel/hung_task.c:380
 kthread+0x2f0/0x390 kernel/kthread.c:388
 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5378 Comm: syz-executor.0 Not tainted 6.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:235 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x8/0x90 kernel/kcov.c:290
Code: cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 <65> 48 8b 14 25 80 d3 03 00 65 8b 05 80 c1 6f 7e a9 00 01 ff 00 74
RSP: 0018:ffffc90004837668 EFLAGS: 00000202
RAX: ffff888065ae7801 RBX: ffff88801cc90900 RCX: ffffffff82176b35
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 0000000000000001 R08: ffffffff82176b4e R09: 1ffff1100cb5cf05
R10: dffffc0000000000 R11: ffffed100cb5cf06 R12: 0000000000000008
R13: ffff88801cc90000 R14: 0000000000000200 R15: ffff888065ae7828
FS:  000055555ac67480(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563fd4d26600 CR3: 000000006f02c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 _test_bit_acquire include/asm-generic/bitops/instrumented-non-atomic.h:154 [inline]
 buffer_uptodate include/linux/buffer_head.h:171 [inline]
 __bread_gfp+0xde/0x430 fs/buffer.c:1476
 sb_bread include/linux/buffer_head.h:321 [inline]
 __exfat_ent_get fs/exfat/fatent.c:48 [inline]
 exfat_ent_get+0x14d/0x400 fs/exfat/fatent.c:97
 exfat_readdir fs/exfat/dir.c:187 [inline]
 exfat_iterate+0x1376/0x33e0 fs/exfat/dir.c:261
 wrap_directory_iterator+0x94/0xe0 fs/readdir.c:67
 iterate_dir+0x539/0x6f0 fs/readdir.c:110
 __do_sys_getdents64 fs/readdir.c:409 [inline]
 __se_sys_getdents64+0x20d/0x4f0 fs/readdir.c:394
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x88/0x170 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f60794a9263
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 32 8b fa 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 b0 ff ff ff f7 d8
RSP: 002b:00007fff0a247078 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 000055555ac70970 RCX: 00007f60794a9263
RDX: 0000000000008000 RSI: 000055555ac70970 RDI: 0000000000000005
RBP: 000055555ac70944 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000293 R12: ffffffffffffffb0
R13: 0000000000000010 R14: 000055555ac70940 R15: 0000000000000003
 </TASK>