CVE-2025-68369: Undefined Security Weakness

In the Linux kernel, the following vulnerability has been resolved:

ntfs3: init run lock for extend inode

After setting the inode mode of $Extend to a regular file, executing the truncate system call will enter the do_truncate() routine, causing the run_lock uninitialized error reported by syzbot.

Prior to patch 4e8011ffec79, if the inode mode of $Extend was not set to a regular file, the do_truncate() routine would not be entered.

Add the run_lock initialization when loading $Extend.

syzbot reported: INFO: trying to register non-static key. Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 assign_lock_key+0x133/0x150 kernel/locking/lockdep.c:984 register_lock_class+0x105/0x320 kernel/locking/lockdep.c:1299 __lock_acquire+0x99/0xd20 kernel/locking/lockdep.c:5112 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ntfs_set_size+0x140/0x200 fs/ntfs3/inode.c:860 ntfs_extend+0x1d9/0x970 fs/ntfs3/file.c:387 ntfs_setattr+0x2e8/0xbe0 fs/ntfs3/file.c:808