The Linux kernel's erofs filesystem had a vulnerability (CVE-2026-64146) where the metabuf used in inode xattr initialization could leak due to improper cleanup on certain error paths after calling erofs_read_metabuf(). Specifically, the metabuf reference was not dropped before exiting via out_unlock, causing a folio reference leak. The fix consolidates cleanup at out_unlock, ensuring erofs_put_metabuf() is called when needed, preventing the leak.

The vulnerability causes a memory leak in kernel space related to the erofs filesystem's handling of inode extended attributes. While this does not directly indicate code execution or privilege escalation, memory leaks in kernel code can degrade system stability or lead to resource exhaustion over time.

A fix has been applied in the Linux kernel source code to address this metabuf leak. Since no explicit patch links or vendor advisories are provided, users should update to the Linux kernel version that includes commit bb88e8da0025 or later. Patch status is not yet confirmed from vendor advisories; check the official Linux kernel repositories or vendor advisories for the fixed version and apply updates accordingly.