loop4: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.4.578/8197 is trying to acquire lock:
ffff88807d342800 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0xc5/0x140 mm/memory.c:7177

but task is already holding lock:
ffff88807775acb0 (&ni->ni_lock/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
ffff88807775acb0 (&ni->ni_lock/5){+.+.}-{4:4}, at: ntfs_fiemap+0x131/0x170 fs/ntfs3/file.c:1417

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->ni_lock/5){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:614 [inline]
       __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776
       ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
       attr_data_get_block+0x36e/0x1cc0 fs/ntfs3/attrib.c:918
       ntfs_file_mmap_prepare+0x5f1/0x830 fs/ntfs3/file.c:393
       vfs_mmap_prepare include/linux/fs.h:2060 [inline]
       call_mmap_prepare mm/vma.c:2637 [inline]
       __mmap_region+0xe7f/0x2820 mm/vma.c:2736
       mmap_region+0x30a/0x3e0 mm/vma.c:2830
       do_mmap+0xc63/0x12f0 mm/mmap.c:558
       vm_mmap_pgoff+0x29e/0x470 mm/util.c:581
       ksys_mmap_pgoff+0x328/0x5b0 mm/mmap.c:604
       __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
       __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
       __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x17c/0x330 kernel/locking/lockdep.c:5825
       __might_fault+0xde/0x140 mm/memory.c:7177
       _inline_copy_to_user include/linux/uaccess.h:201 [inline]
       _copy_to_user+0x2d/0xd0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:236 [inline]
       fiemap_fill_next_extent+0x22e/0x380 fs/ioctl.c:144
       ni_fiemap+0xa1d/0xbf0 fs/ntfs3/frecord.c:1898
       ntfs_fiemap+0x144/0x170 fs/ntfs3/file.c:1419
       ioctl_fiemap fs/ioctl.c:219 [inline]
       do_vfs_ioctl+0x683/0x13e0 fs/ioctl.c:531
       __do_sys_ioctl fs/ioctl.c:595 [inline]
       __se_sys_ioctl fs/ioctl.c:583 [inline]
       __x64_sys_ioctl+0x114/0x210 fs/ioctl.c:583
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ni->ni_lock/5);
                               lock(&mm->mmap_lock);
                               lock(&ni->ni_lock/5);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz.4.578/8197:
 #0: ffff88807775acb0 (&ni->ni_lock/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
 #0: ffff88807775acb0 (&ni->ni_lock/5){+.+.}-{4:4}, at: ntfs_fiemap+0x131/0x170 fs/ntfs3/file.c:1417

stack backtrace:
CPU: 1 UID: 0 PID: 8197 Comm: syz.4.578 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043
 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x17c/0x330 kernel/locking/lockdep.c:5825
 __might_fault+0xde/0x140 mm/memory.c:7177
 _inline_copy_to_user include/linux/uaccess.h:201 [inline]
 _copy_to_user+0x2d/0xd0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:236 [inline]
 fiemap_fill_next_extent+0x22e/0x380 fs/ioctl.c:144
 ni_fiemap+0xa1d/0xbf0 fs/ntfs3/frecord.c:1898
 ntfs_fiemap+0x144/0x170 fs/ntfs3/file.c:1419
 ioctl_fiemap fs/ioctl.c:219 [inline]
 do_vfs_ioctl+0x683/0x13e0 fs/ioctl.c:531
 __do_sys_ioctl fs/ioctl.c:595 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x114/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f88df39aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f88e02a1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f88df615fa0 RCX: 00007f88df39aeb9
RDX: 0000200000000040 RSI: 00000000c020660b RDI: 0000000000000004
RBP: 00007f88df408c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f88df616038 R14: 00007f88df615fa0 R15: 00007ffdf59da978
 </TASK>