CVE-2025-38267: In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Do not trigger WARN_ON() due to a commit

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Do not trigger WARN_ON() due to a commit_overrun When reading a memory mapped

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Do not trigger WARN_ON() due to a commit_overrun When reading a memory mapped buffer the reader page is just swapped out with the last page written in the write buffer. If the reader page is the same as the commit buffer (the buffer that is currently being written to) it was assumed that it should never have missed events. If it does, it triggers a WARN_ON_ONCE(). But there just happens to be one scenario where this can legitimately happen. That is on a commit_overrun. A commit overrun is when an interrupt preempts an event being written to the buffer and then the interrupt adds so many new events that it fills and wraps the buffer back to the commit. Any new events would then be dropped and be reported as "missed_events". In this case, the next page to read is the commit buffer and after the swap of the reader page, the reader page will be the commit buffer, but this time there will be missed events and this triggers the following warning: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1127 at kernel/trace/ring_buffer.c:7357 ring_buffer_map_get_reader+0x49a/0x780 Modules linked in:

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.21%, higher than 11% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 31, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

Weekly security brief

The flaws that hit local websites, every Friday.

One short email: what got exploited this week, which WordPress plugins broke, and what to check. Unsubscribe in one click.