syzbot

syz.0.17[5934]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set
loop0: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5934 is trying to acquire lock:
ffff88802426baa0 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0xaa/0x120 mm/memory.c:5968

but task is already holding lock:
ffff88807140ad40 (&ni->ni_lock#3/5){+.+.}-{3:3}, at: ni_lock fs/ntfs3/ntfs_fs.h:1120 [inline]
ffff88807140ad40 (&ni->ni_lock#3/5){+.+.}-{3:3}, at: ntfs_fiemap+0xc8/0x130 fs/ntfs3/file.c:1218

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->ni_lock#3/5){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
       ni_lock fs/ntfs3/ntfs_fs.h:1120 [inline]
       attr_data_get_block+0x31a/0x2000 fs/ntfs3/attrib.c:920
       ntfs_file_mmap+0x4e7/0x7a0 fs/ntfs3/file.c:294
       call_mmap include/linux/fs.h:2023 [inline]
       mmap_file mm/internal.h:98 [inline]
       __mmap_region mm/mmap.c:2790 [inline]
       mmap_region+0xfa2/0x2090 mm/mmap.c:2941
       do_mmap+0x98f/0x10a0 mm/mmap.c:1385
       vm_mmap_pgoff+0x1c4/0x3f0 mm/util.c:556
       ksys_mmap_pgoff+0x4c9/0x720 mm/mmap.c:1431
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
       __might_fault+0xc6/0x120 mm/memory.c:5968
       _copy_to_user+0x2a/0xa0 lib/usercopy.c:36
       copy_to_user include/linux/uaccess.h:191 [inline]
       fiemap_fill_next_extent+0x1de/0x3b0 fs/ioctl.c:145
       ni_fiemap+0x97a/0xc70 fs/ntfs3/frecord.c:2062
       ntfs_fiemap+0xdb/0x130 fs/ntfs3/file.c:1220
       ioctl_fiemap fs/ioctl.c:220 [inline]
       do_vfs_ioctl+0x14fe/0x1cc0 fs/ioctl.c:811
       __do_sys_ioctl fs/ioctl.c:869 [inline]
       __se_sys_ioctl+0x83/0x170 fs/ioctl.c:857
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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.0.17/5934:
 #0: ffff88807140ad40 (&ni->ni_lock#3/5){+.+.}-{3:3}, at: ni_lock fs/ntfs3/ntfs_fs.h:1120 [inline]
 #0: ffff88807140ad40 (&ni->ni_lock#3/5){+.+.}-{3:3}, at: ntfs_fiemap+0xc8/0x130 fs/ntfs3/file.c:1218

stack backtrace:
CPU: 0 PID: 5934 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __might_fault+0xc6/0x120 mm/memory.c:5968
 _copy_to_user+0x2a/0xa0 lib/usercopy.c:36
 copy_to_user include/linux/uaccess.h:191 [inline]
 fiemap_fill_next_extent+0x1de/0x3b0 fs/ioctl.c:145
 ni_fiemap+0x97a/0xc70 fs/ntfs3/frecord.c:2062
 ntfs_fiemap+0xdb/0x130 fs/ntfs3/file.c:1220
 ioctl_fiemap fs/ioctl.c:220 [inline]
 do_vfs_ioctl+0x14fe/0x1cc0 fs/ioctl.c:811
 __do_sys_ioctl fs/ioctl.c:869 [inline]
 __se_sys_ioctl+0x83/0x170 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcee299ce59
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:00007ffe44530348 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcee2c15fa0 RCX: 00007fcee299ce59
RDX: 0000200000000340 RSI: 00000000c020660b RDI: 0000000000000006
RBP: 00007fcee2a32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcee2c15fac R14: 00007fcee2c15fa0 R15: 00007fcee2c15fa0
 </TASK>