CVE-2026-23352 x86/efi: defer freeing of boot services memory

In the Linux kernel, the following vulnerability has been resolved: x86/efi: defer freeing of boot services memory efifreebootservices frees memory occupied by EFIBOOTSERVICESCODE and EFIBOOTSERVICESDATA using memblockfreelate. There are two issue with that: memblockfreelate should be used for...

CVE-2026-23352

CVE-2026-23352 affects Linux kernel's x86 EFI code: efi_free_boot_services() defers freeing of EFI_BOOT_SERVICES memory, but memblock_free_late() is not suitable for reserved memory and may miss uninitialized memory maps when CONFIG_DEFERRED_STRUCT_PAGE_INIT=y. This can cause a RAM leak (~140 MB ...