syzbot

======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0 Not tainted
------------------------------------------------------
syz-executor319/5839 is trying to acquire lock:
ffff88807a42c7e0 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0xb0/0x130 mm/memory.c:6971

but task is already holding lock:
ffff8880764ee7d0 (&ni->ni_lock#3/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1100 [inline]
ffff8880764ee7d0 (&ni->ni_lock#3/5){+.+.}-{4:4}, at: ntfs_fiemap+0xc7/0x130 fs/ntfs3/file.c:1288

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->ni_lock#3/5){+.+.}-{4:4}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
       __mutex_lock_common kernel/locking/mutex.c:602 [inline]
       __mutex_lock+0x182/0xe80 kernel/locking/mutex.c:747
       ni_lock fs/ntfs3/ntfs_fs.h:1100 [inline]
       attr_data_get_block+0x2ec/0x1ec0 fs/ntfs3/attrib.c:918
       ntfs_file_mmap+0x489/0x730 fs/ntfs3/file.c:305
       call_mmap include/linux/fs.h:2286 [inline]
       mmap_file mm/internal.h:167 [inline]
       __mmap_new_file_vma mm/vma.c:2405 [inline]
       __mmap_new_vma mm/vma.c:2467 [inline]
       __mmap_region mm/vma.c:2622 [inline]
       mmap_region+0x1277/0x1f30 mm/vma.c:2692
       do_mmap+0xc45/0x10d0 mm/mmap.c:561
       vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579
       ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 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:3168 [inline]
       check_prevs_add kernel/locking/lockdep.c:3287 [inline]
       validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911
       __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
       __might_fault+0xcc/0x130 mm/memory.c:6971
       _inline_copy_to_user include/linux/uaccess.h:192 [inline]
       _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:225 [inline]
       fiemap_fill_next_extent+0x1c0/0x390 fs/ioctl.c:145
       ni_fiemap+0x89c/0xbf0 fs/ntfs3/frecord.c:2007
       ntfs_fiemap+0xda/0x130 fs/ntfs3/file.c:1290
       ioctl_fiemap fs/ioctl.c:220 [inline]
       do_vfs_ioctl+0x16d3/0x1990 fs/ioctl.c:841
       __do_sys_ioctl fs/ioctl.c:905 [inline]
       __se_sys_ioctl+0x82/0x170 fs/ioctl.c:893
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 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#3/5);
                               lock(&mm->mmap_lock);
                               lock(&ni->ni_lock#3/5);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz-executor319/5839:
 #0: ffff8880764ee7d0 (&ni->ni_lock#3/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1100 [inline]
 #0: ffff8880764ee7d0 (&ni->ni_lock#3/5){+.+.}-{4:4}, at: ntfs_fiemap+0xc7/0x130 fs/ntfs3/file.c:1288

stack backtrace:
CPU: 0 UID: 0 PID: 5839 Comm: syz-executor319 Not tainted 6.16.0-rc5-syzkaller-00266-g3f31a806a62e #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3168 [inline]
 check_prevs_add kernel/locking/lockdep.c:3287 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
 __might_fault+0xcc/0x130 mm/memory.c:6971
 _inline_copy_to_user include/linux/uaccess.h:192 [inline]
 _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 fiemap_fill_next_extent+0x1c0/0x390 fs/ioctl.c:145
 ni_fiemap+0x89c/0xbf0 fs/ntfs3/frecord.c:2007
 ntfs_fiemap+0xda/0x130 fs/ntfs3/file.c:1290
 ioctl_fiemap fs/ioctl.c:220 [inline]
 do_vfs_ioctl+0x16d3/0x1990 fs/ioctl.c:841
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7eff59f1eed9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 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:00007fffa0c263c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000200000000040 RCX: 00007eff59f1eed9
RDX: 0000200000000340 RSI: 00000000c020660b RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 000055558585d4c0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007eff59f6803b
 </TASK>