CVE-2026-23052

CVE-2026-23052 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

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(). Extra allocated pages for ftrace WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:7276 ftrace_process_locs+0x548/0x580 Use the actual capacity of a page group to determine the number of pages to allocate. Have ftrace_allocate_pages() return the number of allocated pages to avoid having to calculate it. Use the actual page group capacity when validating the number of unused pages due to skipped entries. Drop the definition of ENTRIES_PER_PAGE since it is no longer used.

Frequently asked questions

What is CVE-2026-23052?
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(). Extra allocated pages for ftrace WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:7276 ftrace_process_locs+0x548/0x580 Use the actual capacity of a page group to determine the number of pages to allocate. Have ftrace_allocate_pages() return the number of allocated pages to avoid having to calculate it. Use the actual page group capacity when validating the number of unused pages due to skipped entries. Drop the definition of ENTRIES_PER_PAGE since it is no longer used.
Is CVE-2026-23052 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-23052?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-23052 have an EU (EUVD) identifier?
Yes. CVE-2026-23052 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5494.
When was CVE-2026-23052 published?
CVE-2026-23052 was published on 2026-02-04 and last updated on 2026-07-04.

References