CVE-2026-45851

About vulnerability

In the Linux kernel, the following vulnerability has been resolved: efi: Fix reservation of unaccepted memory table The reserve_unaccepted() function incorrectly calculates the size of the memblock reservation for the unaccepted memory table. It aligns the size of the table, but fails to account for cases where the table’s starting physical address (efi.unaccepted) is not page-aligned. If the table starts at an offset within a page and its end crosses into a subsequent page that the aligned size does not cover, the end of the table will not be reserved. This can lead to the table being overwritten or inaccessible, causing a kernel panic in accept_memory(). This issue was observed when starting Intel TDX VMs with specific memory sizes (e.g., > 64GB). Fix this by calculating the end address first (including the unaligned start) and then aligning it up, ensuring the entire range is covered by the reservation. A flaw was found in the Linux kernel’s Extensible Firmware Interface (EFI) subsystem. An error in memory reservation for the unaccepted memory table can occur if its starting address is not page-aligned. This vulnerability could lead to the memory table being overwritten or inaccessible, resulting in a kernel panic and system instability. This issue primarily affects Intel Trust Domain Extensions (TDX) virtual machines with certain memory sizes.

Live-patch status from KernelCare for each operating system.