Linux Kernel EUVD-2026-24898

Upgrade affected Linux kernels to patched versions: 6.18.21 or later, 6.19.11 or later, or 6.12.80 or later depending on deployed stable branch. For users unable to immediately patch, the mitigation is to avoid file-backed EROFS mounts in favor of block-backed EROFS mounts, or to use alternative filesystems such as ext4 or XFS. File-backed EROFS is primarily used in specific embedded or container scenarios, so most production systems can defer patching if block-backed mounts are already in use. The fix is available via standard Linux kernel update mechanisms (apt/yum/dnf depending on distribution). Commit references for cherry-picking are available at https://git.kernel.org/stable/ with the commit hashes provided in references. No workaround exists for systems that require file-backed EROFS functionality; patching is mandatory for those deployments.