CVE-2026-63812
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix incorrect FI_NO_EXTENT handling in __destroy_extent_node() When __destroy_extent_node() sets the inode flag FI_NO_EXTENT, it does not reset the length of the largest extent to 0 and update the inode folio. Since modifications to the extent tree are disallowed afterward, the cached largest extent may become stale. This can trigger the following error in xfstests generic/388: F2FS-fs (dm-0): sanity_check_extent_cache: inode (ino=1761) extent info [220057, 57, 6] is incorrect, run fsck to fix In the f2fs_drop_inode path, __destroy_extent_node() does not need to guarantee that et->node_cnt is 0, because concurrency with writeback is expected in this path, and writeback may update the extent cache. This patch reverts commit ed78aeebef05 ("f2fs: fix node_cnt race between extent node destroy and writeback"), and remove the unnecessary zero check of et->node_cnt.
Affected versions
Linux kernel versions
6.6.140,
6.12.88,
6.18.30,
7.0.7,
7.1
and later are affected. Fixed in
6.6.144,
6.12.95,
6.18.38,
7.1.3,
7.2-rc1
and their respective stable series.
References
5 totalFrequently asked questions
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What is CVE-2026-63812?
CVE-2026-63812 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.6.140 onward and has been patched in 6.6.144, 6.12.95, 6.18.38 and others. CVE-2026-63812 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-63812?
Yes — CVE-2026-63812 has been patched. Fixed versions include 6.6.144, 6.12.95, 6.18.38 and others. If you are running Linux kernel 6.6.140 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-63812 actively exploited?
No — CVE-2026-63812 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.