Linux Kernel EUVD-2026-26556

Apply vendor-released patches immediately for affected kernel versions: upgrade to Linux kernel 6.12.81 or later for 6.12.x branch, 6.18.22 or later for 6.18.x branch, 6.19.12 or later for 6.19.x branch, or 7.0 for mainline. Patches correct the buffer size calculations in dma_alloc_coherent and memcpy operations within the zynqmp_nvmem driver. Review upstream commits at https://git.kernel.org/stable/c/784ed4abded1ca4b525fa4cade8b02f8c5d2a087 (and related commits 6c01e7f11f5e, 2f6e5b9964d0, f9b88613ff40) for technical details. If immediate patching is not feasible for embedded systems with constrained update cycles, disable the zynqmp_nvmem driver via kernel module blacklisting (add 'blacklist zynqmp_nvmem' to /etc/modprobe.d/blacklist.conf and rebuild initramfs), though this eliminates NVMEM functionality and may break system features dependent on non-volatile storage access. Implement kernel address space layout randomization (KASLR) if not already enabled to increase exploitation difficulty, though this only raises the bar rather than eliminating the vulnerability. Restrict local user access and monitor for unusual privilege escalation attempts in systems that cannot be immediately patched.