Linux hwe edge: (In the Linux kernel, the following vulnerability has been resolved: K ...) (CVE-2026-80853)

The Linux kernel vulnerability CVE-2026-80853 relates to the KVM SEV feature on SNP-enabled hosts. When encrypting or decrypting memory of SEV or SEV-ES guests, the kernel used temporary buffers that were not allocated as full 4KiB pages. Because SNP architecture requires pages involved in firmware writes to be fully assigned to Firmware, sub-page allocations allowed other kernel components to access parts of the same page concurrently. This caused spurious RMP page fault violations and kernel panics due to attempts to write to Firmware-owned memory. The fix ensures that temporary buffers for these operations are allocated as full pages to prevent concurrent access and page faults.

This vulnerability could lead to kernel crashes or panics on SNP-enabled hosts running SEV or SEV-ES guests due to improper memory page ownership and access violations. Such crashes could disrupt virtual machine operations and potentially affect host stability. There is no indication of direct code execution or privilege escalation from the provided data.

A fix has been implemented in the Linux kernel to allocate full 4KiB pages for temporary buffers used in SEV/SEV-ES memory encryption and decryption on SNP-enabled hosts. Users should update to a kernel version that includes this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the official Linux kernel advisories or vendor updates for the exact fixed versions and apply the official patch accordingly.