CVE-2026-63812

About vulnerability

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 product:

AlmaLinux 9.2 ESU , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , RHEL 7 ELS , TuxCare 9.6 ESU

Affected packages:

kernel @ 3.10.0 (+6 more)

Live-patch status from KernelCare for each operating system.