Linux Kernel EUVD-2026-26524

Upgrade to patched Linux kernel versions: 6.18.25 or later in the 6.x stable series, 7.0.2 or later in the 7.0 stable series, or 7.1-rc1 and later in the development branch. Apply vendor-provided kernel updates containing commits 188bb65f247a, 963d2e24d9d9, or 2d9c4a4ed4ee depending on your kernel branch. Patch details at https://git.kernel.org/stable/c/188bb65f247a7a7c62f287c9a263aee3cad96fa5. The fix reorders operations in f2fs_write_end_io() to call f2fs_in_warm_node_list() before decrementing the page counter, closing the race window. If immediate patching is not feasible, consider disabling F2FS filesystem support if not actively used (filesystem can be disabled in kernel configuration via CONFIG_F2FS_FS), though this breaks functionality for systems relying on F2FS. Avoid frequent mount/unmount cycles of F2FS filesystems during heavy write I/O operations to reduce race condition triggering probability, though this is operationally impractical for most use cases. No application-layer mitigations exist as this is a kernel-internal race condition. Monitor kernel crash logs for NULL pointer dereferences in f2fs_in_warm_node_list or f2fs_write_end_io as potential exploitation indicators.