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Subject[syzbot] [ntfs?] possible deadlock in __ntfs_cluster_free
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Hello,

syzbot found the following issue on:

HEAD commit: 2258c2dc850b Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1543182a480000
kernel config: https://syzkaller.appspot.com/x/.config?x=68e0be42c8ee4bb4
dashboard link: https://syzkaller.appspot.com/bug?extid=6a2409526a801cf8c0ef
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/aee4b2292a64/disk-2258c2dc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9ecfc816182c/vmlinux-2258c2dc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f24ffaf1255a/bzImage-2258c2dc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6a2409526a801cf8c0ef@syzkaller.appspotmail.com

ntfs: volume version 3.1.
======================================================
WARNING: possible circular locking dependency detected
6.2.0-rc1-syzkaller-00043-g2258c2dc850b #0 Not tainted
------------------------------------------------------
syz-executor.3/28063 is trying to acquire lock:
ffff88801e35d9f8 (&vol->lcnbmp_lock){+.+.}-{3:3}, at: __ntfs_cluster_free+0xd4/0x890 fs/ntfs/lcnalloc.c:862

but task is already holding lock:
ffff888039ccc390 (&lcnbmp_mrec_lock_key){+.+.}-{3:3}, at: map_mft_record+0x46/0x610 fs/ntfs/mft.c:154

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&lcnbmp_mrec_lock_key){+.+.}-{3:3}:
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
__mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
map_mft_record+0x46/0x610 fs/ntfs/mft.c:154
__ntfs_write_inode+0x80/0xc90 fs/ntfs/inode.c:2978
ntfs_commit_inode fs/ntfs/inode.h:300 [inline]
ntfs_put_super+0x3ba/0xf80 fs/ntfs/super.c:2283
generic_shutdown_super+0x130/0x310 fs/super.c:492
kill_block_super+0x79/0xd0 fs/super.c:1386
deactivate_locked_super+0xa7/0xf0 fs/super.c:332
cleanup_mnt+0x494/0x520 fs/namespace.c:1291
task_work_run+0x243/0x300 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0x124/0x150 kernel/entry/common.c:171
exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296
do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&vol->lcnbmp_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
__lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
down_write+0x9c/0x270 kernel/locking/rwsem.c:1562
__ntfs_cluster_free+0xd4/0x890 fs/ntfs/lcnalloc.c:862
ntfs_cluster_free fs/ntfs/lcnalloc.h:96 [inline]
ntfs_truncate+0x119c/0x2720 fs/ntfs/inode.c:2695
ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
ntfs_setattr+0x2b9/0x3a0 fs/ntfs/inode.c:2914
notify_change+0xe50/0x1100 fs/attr.c:482
do_truncate+0x200/0x2f0 fs/open.c:65
handle_truncate fs/namei.c:3216 [inline]
do_open fs/namei.c:3561 [inline]
path_openat+0x272b/0x2dd0 fs/namei.c:3714
do_file_open_root+0x339/0x790 fs/namei.c:3766
file_open_root+0x234/0x290 fs/open.c:1290
do_handle_open+0x565/0x950 fs/fhandle.c:232
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&lcnbmp_mrec_lock_key);
lock(&vol->lcnbmp_lock);
lock(&lcnbmp_mrec_lock_key);
lock(&vol->lcnbmp_lock);

*** DEADLOCK ***

4 locks held by syz-executor.3/28063:
#0: ffff888038f60460 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:508
#1: ffff888039ccc670 (&sb->s_type->i_mutex_key#33){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
#1: ffff888039ccc670 (&sb->s_type->i_mutex_key#33){+.+.}-{3:3}, at: do_truncate+0x1ec/0x2f0 fs/open.c:63
#2: ffff888039ccc300 (&lcnbmp_runlist_lock_key){++++}-{3:3}, at: ntfs_truncate+0x1d8/0x2720 fs/ntfs/inode.c:2378
#3: ffff888039ccc390 (&lcnbmp_mrec_lock_key){+.+.}-{3:3}, at: map_mft_record+0x46/0x610 fs/ntfs/mft.c:154

stack backtrace:
CPU: 0 PID: 28063 Comm: syz-executor.3 Not tainted 6.2.0-rc1-syzkaller-00043-g2258c2dc850b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2177
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
__lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
down_write+0x9c/0x270 kernel/locking/rwsem.c:1562
__ntfs_cluster_free+0xd4/0x890 fs/ntfs/lcnalloc.c:862
ntfs_cluster_free fs/ntfs/lcnalloc.h:96 [inline]
ntfs_truncate+0x119c/0x2720 fs/ntfs/inode.c:2695
ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
ntfs_setattr+0x2b9/0x3a0 fs/ntfs/inode.c:2914
notify_change+0xe50/0x1100 fs/attr.c:482
do_truncate+0x200/0x2f0 fs/open.c:65
handle_truncate fs/namei.c:3216 [inline]
do_open fs/namei.c:3561 [inline]
path_openat+0x272b/0x2dd0 fs/namei.c:3714
do_file_open_root+0x339/0x790 fs/namei.c:3766
file_open_root+0x234/0x290 fs/open.c:1290
do_handle_open+0x565/0x950 fs/fhandle.c:232
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f169e08c0a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f169ee1f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000130
RAX: ffffffffffffffda RBX: 00007f169e1abf80 RCX: 00007f169e08c0a9
RDX: 0000000000000202 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f169e0e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffecb030f6f R14: 00007f169ee1f300 R15: 0000000000022000
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

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