syzbot

ntfs: (device loop4): ntfs_read_block(): Failed to read from inode 0xa, attribute type 0x80, vcn 0x1, offset 0x0 because its location on disk could not be determined even after retrying (error code -5).
ntfs: (device loop4): ntfs_mapping_pairs_decompress(): Corrupt attribute.
ntfs: volume version 3.1.
======================================================
WARNING: possible circular locking dependency detected
5.15.185-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.92/4647 is trying to acquire lock:
ffff88805f645c50 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x4e/0x620 fs/ntfs/mft.c:154

but task is already holding lock:
ffff88805f645bc0 (&rl->lock){++++}-{3:3}, at: ntfs_truncate+0x20e/0x27c0 fs/ntfs/inode.c:2378

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&rl->lock){++++}-{3:3}:
       down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
       ntfs_read_block fs/ntfs/aops.c:248 [inline]
       ntfs_readpage+0x1277/0x2220 fs/ntfs/aops.c:435
       do_read_cache_page+0x8a1/0x1030 mm/filemap.c:-1
       read_mapping_page include/linux/pagemap.h:515 [inline]
       ntfs_map_page+0x24/0x390 fs/ntfs/aops.h:75
       ntfs_sync_mft_mirror+0x24a/0x19e0 fs/ntfs/mft.c:480
       write_mft_record_nolock+0x1223/0x17e0 fs/ntfs/mft.c:787
       write_mft_record fs/ntfs/mft.h:95 [inline]
       __ntfs_write_inode+0x7cb/0xdc0 fs/ntfs/inode.c:3050
       write_inode fs/fs-writeback.c:1495 [inline]
       __writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1705
       writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1930
       wb_writeback+0x443/0xb90 fs/fs-writeback.c:2104
       wb_do_writeback fs/fs-writeback.c:2247 [inline]
       wb_workfn+0x423/0xe60 fs/fs-writeback.c:2288
       process_one_work+0x863/0x1000 kernel/workqueue.c:2310
       worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
       kthread+0x436/0x520 kernel/kthread.c:334
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

-> #0 (&ni->mrec_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       map_mft_record+0x4e/0x620 fs/ntfs/mft.c:154
       ntfs_truncate+0x280/0x27c0 fs/ntfs/inode.c:2383
       ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
       ntfs_setattr+0x2bc/0x3a0 fs/ntfs/inode.c:2914
       notify_change+0xbcd/0xee0 fs/attr.c:505
       do_truncate+0x197/0x220 fs/open.c:65
       vfs_truncate+0x262/0x2f0 fs/open.c:111
       do_sys_truncate+0xdc/0x190 fs/open.c:134
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rl->lock);
                               lock(&ni->mrec_lock);
                               lock(&rl->lock);
  lock(&ni->mrec_lock);

 *** DEADLOCK ***

3 locks held by syz.4.92/4647:
 #0: ffff8880220ba460 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377
 #1: ffff88805f645f30 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88805f645f30 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: do_truncate+0x183/0x220 fs/open.c:63
 #2: ffff88805f645bc0 (&rl->lock){++++}-{3:3}, at: ntfs_truncate+0x20e/0x27c0 fs/ntfs/inode.c:2378

stack backtrace:
CPU: 0 PID: 4647 Comm: syz.4.92 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 map_mft_record+0x4e/0x620 fs/ntfs/mft.c:154
 ntfs_truncate+0x280/0x27c0 fs/ntfs/inode.c:2383
 ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
 ntfs_setattr+0x2bc/0x3a0 fs/ntfs/inode.c:2914
 notify_change+0xbcd/0xee0 fs/attr.c:505
 do_truncate+0x197/0x220 fs/open.c:65
 vfs_truncate+0x262/0x2f0 fs/open.c:111
 do_sys_truncate+0xdc/0x190 fs/open.c:134
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f81908cf929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f818e737038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f8190af6fa0 RCX: 00007f81908cf929
RDX: 0000000000000000 RSI: 0000000000001fff RDI: 0000200000000080
RBP: 00007f8190951b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8190af6fa0 R15: 00007ffe13fe61a8
 </TASK>