CVE-2025-40101: In the Linux kernel, the following vulnerability has been resolved: btrfs: fix memory leaks when rejecting a non SINGLE data profile without an RST At the end

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix memory leaks when rejecting a non SINGLE data profile without an RST At the end

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix memory leaks when rejecting a non SINGLE data profile without an RST At the end of btrfs_load_block_group_zone_info() the first thing we do is to ensure that if the mapping type is not a SINGLE one and there is no RAID stripe tree, then we return early with an error. Doing that, though, prevents the code from running the last calls from this function which are about freeing memory allocated during its run. Hence, in this case, instead of returning early, we set the ret value and fall through the rest of the cleanup code.

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 0.20%, higher than 9% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 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.

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