loop7: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.7.1931/23805 is trying to acquire lock:
ffff88803d48f670 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0xaf/0x130 mm/memory.c:7177

but task is already holding lock:
ffff888064caec90 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
ffff888064caec90 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_fiemap+0x10a/0x1a0 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#2/5){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
       ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
       attr_data_get_block+0x2f1/0x1e90 fs/ntfs3/attrib.c:918
       ntfs_file_mmap_prepare+0x55f/0x8b0 fs/ntfs3/file.c:393
       vfs_mmap_prepare include/linux/fs.h:2060 [inline]
       call_mmap_prepare mm/vma.c:2637 [inline]
       __mmap_region mm/vma.c:2736 [inline]
       mmap_region+0xc7c/0x1f50 mm/vma.c:2830
       do_mmap+0xc2f/0x10c0 mm/mmap.c:558
       vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581
       ksys_mmap_pgoff+0x4e8/0x720 mm/mmap.c:604
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xe2/0xf80 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
       __might_fault+0xcb/0x130 mm/memory.c:7177
       _inline_copy_to_user include/linux/uaccess.h:201 [inline]
       _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:236 [inline]
       fiemap_fill_next_extent+0x1dd/0x3c0 fs/ioctl.c:144
       ni_fiemap+0x9a5/0xca0 fs/ntfs3/frecord.c:2009
       ntfs_fiemap+0x11d/0x1a0 fs/ntfs3/file.c:1419
       ioctl_fiemap fs/ioctl.c:219 [inline]
       do_vfs_ioctl+0x126f/0x1540 fs/ioctl.c:531
       __do_sys_ioctl fs/ioctl.c:595 [inline]
       __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xe2/0xf80 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#2/5);
                               lock(&mm->mmap_lock);
                               lock(&ni->ni_lock#2/5);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz.7.1931/23805:
 #0: ffff888064caec90 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1127 [inline]
 #0: ffff888064caec90 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_fiemap+0x10a/0x1a0 fs/ntfs3/file.c:1417

stack backtrace:
CPU: 1 UID: 0 PID: 23805 Comm: syz.7.1931 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 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+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
 __might_fault+0xcb/0x130 mm/memory.c:7177
 _inline_copy_to_user include/linux/uaccess.h:201 [inline]
 _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:236 [inline]
 fiemap_fill_next_extent+0x1dd/0x3c0 fs/ioctl.c:144
 ni_fiemap+0x9a5/0xca0 fs/ntfs3/frecord.c:2009
 ntfs_fiemap+0x11d/0x1a0 fs/ntfs3/file.c:1419
 ioctl_fiemap fs/ioctl.c:219 [inline]
 do_vfs_ioctl+0x126f/0x1540 fs/ioctl.c:531
 __do_sys_ioctl fs/ioctl.c:595 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f55a42faeb9
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:00007f55a2556028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f55a4575fa0 RCX: 00007f55a42faeb9
RDX: 0000200000000040 RSI: 00000000c020660b RDI: 0000000000000004
RBP: 00007f55a4368c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55a4576038 R14: 00007f55a4575fa0 R15: 00007fff37312488
 </TASK>
ntfs3(loop7): ino=5, "/" mi_enum_attr
ntfs3(loop7): Mark volume as dirty due to NTFS errors