syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.18/4483 is trying to acquire lock:
ffff88806aeb6840 (&ni->ni_lock/5){+.+.}-{3:3}, at: ni_lock fs/ntfs3/ntfs_fs.h:1102 [inline]
ffff88806aeb6840 (&ni->ni_lock/5){+.+.}-{3:3}, at: attr_data_get_block+0x33b/0x1b70 fs/ntfs3/attrib.c:951

but task is already holding lock:
ffff88801d2aea58
 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:518

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&mm->mmap_lock){++++}-{3:3}:
       __might_fault+0xc2/0x120 mm/memory.c:5852
       _copy_to_user+0x27/0x130 lib/usercopy.c:36
       copy_to_user include/linux/uaccess.h:169 [inline]
       ni_fiemap+0x4ec/0x1300 fs/ntfs3/frecord.c:2140
       ntfs_fiemap+0xd7/0x130 fs/ntfs3/file.c:1173
       ioctl_fiemap fs/ioctl.c:219 [inline]
       do_vfs_ioctl+0x1425/0x1d10 fs/ioctl.c:810
       __do_sys_ioctl fs/ioctl.c:868 [inline]
       __se_sys_ioctl+0x83/0x170 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ni->ni_lock/5){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
       ni_lock fs/ntfs3/ntfs_fs.h:1102 [inline]
       attr_data_get_block+0x33b/0x1b70 fs/ntfs3/attrib.c:951
       ntfs_file_mmap+0x448/0x6d0 fs/ntfs3/file.c:312
       call_mmap include/linux/fs.h:2270 [inline]
       mmap_file+0x5d/0xb0 mm/util.c:1109
       __mmap_region mm/mmap.c:2772 [inline]
       mmap_region+0xe2c/0x1c70 mm/mmap.c:2916
       do_mmap+0x958/0xfd0 mm/mmap.c:1436
       vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
       ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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.1.18/4483:
 #0: ffff88801d2aea58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff88801d2aea58 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:518

stack backtrace:
CPU: 0 PID: 4483 Comm: syz.1.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
 ni_lock fs/ntfs3/ntfs_fs.h:1102 [inline]
 attr_data_get_block+0x33b/0x1b70 fs/ntfs3/attrib.c:951
 ntfs_file_mmap+0x448/0x6d0 fs/ntfs3/file.c:312
 call_mmap include/linux/fs.h:2270 [inline]
 mmap_file+0x5d/0xb0 mm/util.c:1109
 __mmap_region mm/mmap.c:2772 [inline]
 mmap_region+0xe2c/0x1c70 mm/mmap.c:2916
 do_mmap+0x958/0xfd0 mm/mmap.c:1436
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f755198ebe9
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:00007f75528a9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f7551bc5fa0 RCX: 00007f755198ebe9
RDX: 00000000027fffff RSI: 0000000000600000 RDI: 0000200000000000
RBP: 00007f7551a11e19 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000004002011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7551bc6038 R14: 00007f7551bc5fa0 R15: 00007ffe37f024a8
 </TASK>