CVE-2026-89836: In the Linux kernel, the following vulnerability has been resolved: f2fs: fix folio_nr_pages() race after put in large folio invalidate Our v6.18 based Androi

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix folio_nr_pages() race after put in large folio invalidate Our v6.18 based Androi

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix folio_nr_pages() race after put in large folio invalidate Our v6.18 based Android system is continuely suffering livelock and bad page stat as shown in[1] which related to broken xarray slot status. By investigating big folio operations within f2fs, we find below races and fix it by get the nr_pages before drop the refcount and folio_lock. f2fs_get_read_data_folio() calls f2fs_folio_put() before folio_nr_pages() when invalidating a large folio from the page cache. That unlocks the folio and drops the caller reference, leaving a window where a concurrent truncate or folio split can shrink the compound folio or free it before the invalidate range is computed. An undersized range then leaves split sub-folios in mapping->i_pages, which can later interact badly with truncate and reclaim (stale xarray entries and bad page state when folio->mapping no longer matches the mapping being truncated). [1] PID: 2594 TASK: ffffff8169b81580 CPU: 7 COMMAND: "Thread-3" #0 [ffffffc08ef2b8a0] xas_load at ffffffe52d1f42a4 #1 [ffffffc08ef2b900] find_get_entries at ffffffe52c185798 #2 [ffffffc08ef2bb60] truncate_

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 0.17%, higher than 5% 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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