CVE-2026-53047

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

efi/capsule-loader: fix incorrect sizeof in phys array reallocation

The krealloc() call for cap_info->phys in __efi_capsule_setup_info() uses

sizeof(phys_addr_t *) instead of sizeof(phys_addr_t), which might be

causing an undersized allocation.

The allocation is also inconsistent with the initial array allocation in

efi_capsule_open() that allocates one entry with sizeof(phys_addr_t),

and the efi_capsule_write() function that stores phys_addr_t values (not

pointers) via page_to_phys().

On 64-bit systems where sizeof(phys_addr_t) == sizeof(phys_addr_t *), this

goes unnoticed. On 32-bit systems with PAE where phys_addr_t is 64-bit but

pointers are 32-bit, this allocates half the required space, which might

lead to a heap buffer overflow when storing physical addresses.

This is similar to the bug fixed in commit fccfa646ef36 ("efi/capsule-loader:

fix incorrect allocation size") which fixed the same issue at the initi

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References