Linux CVE-2026-43272

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

ring-buffer: Fix possible dereference of uninitialized pointer

There is a pointer head_page in rb_meta_validate_events() which is not initialized at the beginning of a function. This pointer can be dereferenced if there is a failure during reader page validation. In this case the control is passed to "invalid" label where the pointer is dereferenced in a loop.

To fix the issue initialize orig_head and head_page before calling rb_validate_buffer.

Found by Linux Verification Center (linuxtesting.org) with SVACE.