CVE-2026-92502

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the ext4 file system when operating in data=journal mode. During a system reboot, while the superblock is being remounted as read-only, the writeback thread may trigger a warning in the ext4 journal check start() function. This occurs because certain folios (memory pages) may retain stale xarray tags, specifically PAGECACHE TAG DIRTY and PAGECACHE TAG TOWRITE, even after the PG dirty flag has been cleared. In data=journal mode, the jbd2 component checkpoints journaled data to its final location and clears its own dirty flag without updating the folio's PG dirty or xarray dirty flags. Consequently, the writeback thread skips these clean folios in the mpage prepare extent to map() function and fails to reach ext4 bio write folio(), where these stale tags would normally be cleared. This can lead to a warning indicating that data will be lost during inode eviction.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.