syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.18/4411 is trying to acquire lock:
ffff88805928e0e0 (&ni->ni_lock/5){+.+.}-{3:3}, at: ni_lock fs/ntfs3/ntfs_fs.h:1100 [inline]
ffff88805928e0e0 (&ni->ni_lock/5){+.+.}-{3:3}, at: attr_data_get_block+0x2df/0x1880 fs/ntfs3/attrib.c:849

but task is already holding lock:
ffff888076829d28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
ffff888076829d28 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:549

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&mm->mmap_lock){++++}-{3:3}:
       __might_fault+0xb3/0x110 mm/memory.c:5357
       _copy_to_user+0x29/0x130 lib/usercopy.c:35
       copy_to_user include/linux/uaccess.h:200 [inline]
       fiemap_fill_next_extent+0x19d/0x360 fs/ioctl.c:144
       ni_fiemap+0x3a7/0xc20 fs/ntfs3/frecord.c:1902
       ntfs_fiemap+0xd7/0x130 fs/ntfs3/file.c:1236
       ioctl_fiemap fs/ioctl.c:219 [inline]
       do_vfs_ioctl+0x1464/0x1de0 fs/ioctl.c:814
       __do_sys_ioctl fs/ioctl.c:872 [inline]
       __se_sys_ioctl+0x83/0x170 fs/ioctl.c:860
       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

-> #0 (&ni->ni_lock/5){+.+.}-{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
       ni_lock fs/ntfs3/ntfs_fs.h:1100 [inline]
       attr_data_get_block+0x2df/0x1880 fs/ntfs3/attrib.c:849
       ntfs_file_mmap+0x457/0x740 fs/ntfs3/file.c:389
       call_mmap include/linux/fs.h:2177 [inline]
       mmap_file+0x5d/0xb0 mm/util.c:1092
       __mmap_region mm/mmap.c:1796 [inline]
       mmap_region+0xf8f/0x1660 mm/mmap.c:2933
       do_mmap+0x81f/0xea0 mm/mmap.c:1586
       vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:551
       ksys_mmap_pgoff+0x542/0x780 mm/mmap.c:1635
       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(&mm->mmap_lock);
                               lock(&ni->ni_lock/5);
                               lock(&mm->mmap_lock);
  lock(&ni->ni_lock/5);

 *** DEADLOCK ***

1 lock held by syz.1.18/4411:
 #0: ffff888076829d28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff888076829d28 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:549

stack backtrace:
CPU: 1 PID: 4411 Comm: syz.1.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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
 ni_lock fs/ntfs3/ntfs_fs.h:1100 [inline]
 attr_data_get_block+0x2df/0x1880 fs/ntfs3/attrib.c:849
 ntfs_file_mmap+0x457/0x740 fs/ntfs3/file.c:389
 call_mmap include/linux/fs.h:2177 [inline]
 mmap_file+0x5d/0xb0 mm/util.c:1092
 __mmap_region mm/mmap.c:1796 [inline]
 mmap_region+0xf8f/0x1660 mm/mmap.c:2933
 do_mmap+0x81f/0xea0 mm/mmap.c:1586
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:551
 ksys_mmap_pgoff+0x542/0x780 mm/mmap.c:1635
 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: 0033:0x7fbea2a2cba9
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:00007fbea207b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fbea2c74090 RCX: 00007fbea2a2cba9
RDX: 00000000027fffff RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007fbea2aafe19 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000004002011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbea2c74128 R14: 00007fbea2c74090 R15: 00007ffdf57767e8
 </TASK>