CVE-2026-23052

Technical Description

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

ftrace: Do not over-allocate ftrace memory

The pg_remaining calculation in ftrace_process_locs() assumes that

ENTRIES_PER_PAGE multiplied by 2^order equals the actual capacity of the

allocated page group. However, ENTRIES_PER_PAGE is PAGE_SIZE / ENTRY_SIZE

(integer division). When PAGE_SIZE is not a multiple of ENTRY_SIZE (e.g.

4096 / 24 = 170 with remainder 16), high-order allocations (like 256 pages)

have significantly more capacity than 256 * 170. This leads to pg_remaining

being underestimated, which in turn makes skip (derived from skipped -

pg_remaining) larger than expected, causing the WARN(skip != remaining)

to trigger.

Extra allocated pages for ftrace: 2 with 654 skipped

WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:7295 ftrace_process_locs+0x5bf/0x5e0

A similar problem in ftrace_allocate_records() can result in allocating

too many pages. This can trigger the second warning in

ftrace_process_locs().

Ex

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References