CVE-2026-89841

f2fs: only redirty pinned folios in redirty_blocks

CVE-2026-89841 is fixed in linux on 1 platform by DEBIAN-CVE-2026-89841 (version 7.2.6-1), released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
7.8
high
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0017
6th percentile

In the Linux kernel, the following vulnerability has been resolved: f2fs: only redirty pinned folios in redirty_blocks redirty_blocks() pins folios with read_cache_folio() and then walks the same range again with filemap_lock_folio() to redirty them and drop the references it took. Commit 5951fee46bef ("f2fs: Use a folio in redirty_blocks()") changed the second pass to a do/while loop. If read_cache_folio() fails before anything is pinned, page_idx does not advance but the cleanup loop still runs once. If readahead has already populated the failed folio in page cache, that extra iteration finds it and folio_put_refs(folio, 2) drops one reference too many. Later drop_caches or reclaim can then report "BUG: Bad page state". Only redirty the range that was pinned successfully.

Where it's fixed

ProductFixed inFixReleased
Linux
linux · Debian 14 7.2.6-1 DEBIAN-CVE-2026-89841 Sep 23, 2026

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