[v5.15] INFO: task hung in exfat_sync_fs (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 284087d4f7d5 Linux 5.15.158
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16bbf024980000
kernel config: https://syzkaller.appspot.com/x/.config?x=b0dd54e4b5171ebc
dashboard link: https://syzkaller.appspot.com/bug?extid=7337af1738f2164a1633
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c2e33c1db6bf/disk-284087d4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d9f77284af1d/vmlinux-284087d4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a600323dd149/bzImage-284087d4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7337af...@syzkaller.appspotmail.com

INFO: task syz-executor.2:4060 blocked for more than 143 seconds.
Not tainted 5.15.158-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2 state:D stack:25208 pid: 4060 ppid: 3531 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
__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:705
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: 0033:0x7f4c406d5ca9
RSP: 002b:00007f4c3ec060c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f4c40804120 RCX: 00007f4c406d5ca9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4c4072147e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f4c40804120 R15: 00007ffebe5999a8
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
#0: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:1/144:
2 locks held by getty/3268:
#0: ffff88814b157098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by kworker/0:4/3573:
3 locks held by syz-executor.1/4011:
2 locks held by syz-executor.2/4060:
#0: ffff88807bd280e0 (&type->s_umount_key#49){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
#1: ffff8880797620e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_sync_fs+0x67/0x100 fs/exfat/super.c:64
1 lock held by syz-executor.2/4193:
2 locks held by syz-executor.0/6540:
2 locks held by syz-executor.4/6543:
#0: ffff88801b136118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
#1: ffff88801b12b468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2070
3 locks held by syz-executor.1/6547:
#0: ffff88801e6ce370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2cb/0x380 fs/file.c:1088
#1: ffff88807ceba460 (sb_writers#27){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
#2: ffff88805dcf8150 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
#2: ffff88805dcf8150 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}, at: fuse_cache_write_iter fs/fuse/file.c:1311 [inline]
#2: ffff88805dcf8150 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}, at: fuse_file_write_iter+0x2cc/0xd80 fs/fuse/file.c:1611
1 lock held by syz-executor.3/6553:

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

NMI backtrace for cpu 0
CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.15.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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:300
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4193 Comm: syz-executor.2 Not tainted 5.15.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:lockdep_hardirqs_on_prepare+0x1c3/0x7a0 kernel/locking/lockdep.c:4275
Code: 48 c1 e8 03 80 3c 10 00 74 0f e8 78 bf 67 00 48 ba 00 00 00 00 00 fc ff df 4c 89 7c 24 18 48 8b 44 24 10 4c 8b b0 e0 0a 00 00 <48> 8d b8 c8 0a 00 00 48 89 f8 48 c1 e8 03 80 3c 10 00 74 05 e8 c4
RSP: 0018:ffffc9000433fe20 EFLAGS: 00000046
RAX: ffff888056701dc0 RBX: 1ffff92000867fcc RCX: ffffffff913eef03
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8880567028a0
RBP: ffffc9000433fed8 R08: ffffffff8186dcf0 R09: fffffbfff1bc8c56
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 00000000000000e6 R14: ffffffffffffffff R15: 1ffff92000867fc8
FS: 000055555609f480(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555626d938 CR3: 0000000054a4b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49
syscall_enter_from_user_mode+0x2e/0x240 kernel/entry/common.c:113
do_syscall_64+0x1e/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f348b7490b5
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007fffb43bc8b0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000183 RCX: 00007f348b7490b5
RDX: 00007fffb43bc8f0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fffb43bc97c R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 00000000000450b2 R14: 0000000000044fc5 R15: 000000000000000b
</TASK>


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