CVE-2026-89839

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

Description An issue exists in the f2fs file system where the f2fs xattr advise set() function uses an incorrect idmap when calling inode owner or capable() to verify ownership before allowing the system.advise xattr to be set. Because it uses &nop mnt idmap instead of the idmap provided by the VFS, the system checks the caller's fsuid against the unmapped on-disk owner. This can result in the actual owner being denied access with an -EPERM error or an unrelated caller being granted unauthorized access on idmapped mounts.

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