CVE-2025-38715 – hfs: fix slab-out-of-bounds in hfs_bnode_read()

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

hfs: fix slab-out-of-bounds in hfs_bnode_read()

This patch introduces is_bnode_offset_valid() method that checks
the requested offset value. Also, it introduces
check_and_correct_requested_length() method that checks and
correct the requested length (if it is necessary). These methods
are used in hfs_bnode_read(), hfs_bnode_write(), hfs_bnode_clear(),
hfs_bnode_copy(), and hfs_bnode_move() with the goal to prevent
the access out of allocated memory and triggering the crash.