CVE-2025-38702

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

fbdev: fix potential buffer overflow in do_register_framebuffer()

The current implementation may lead to buffer overflow when:
1.  Unregistration creates NULL gaps in registered_fb[]
2.  All array slots become occupied despite num_registered_fb < FB_MAX
3.  The registration loop exceeds array bounds

Add boundary check to prevent registered_fb[FB_MAX] access.