CVE-2024-26678

Description

In the Linux kernel, the following vulnerability has been resolved: x86/efistub: Use 1:1 file:memory mapping for PE/COFF .compat section The .compat section is a dummy PE section that contains the address of the 32-bit entrypoint of the 64-bit kernel image if it is bootable from 32-bit firmware (i.e., CONFIG_EFI_MIXED=y) This section is only 8 bytes in size and is only referenced from the loader, and so it is placed at the end of the memory view of the image, to avoid the need for padding it to 4k, which is required for sections appearing in the middle of the image. Unfortunately, this violates the PE/COFF spec, and even if most EFI loaders will work correctly (including the Tianocore reference implementation), PE loaders do exist that reject such images, on the basis that both the file and memory views of the file contents should be described by the section headers in a monotonically increasing manner without leaving any gaps. So reorganize the sections to avoid this issue. This results in a slight padding overhead (< 4k) which can be avoided if desired by disabling CONFIG_EFI_MIXED (which is only needed in rare cases these days)

References

https://git.kernel.org/stable/c/d327e961573fc335af0ae8a160302205327e1f4e

https://git.kernel.org/stable/c/4adeeff8c12321cd453412a659c3c0eeb9bb2397

https://git.kernel.org/stable/c/1ad55cecf22f05f1c884adf63cc09d3c3e609ebf

https://git.kernel.org/stable/c/0a962f2fbaa976af9eed21d0306370cded485787

Details

Source: Mitre, NVD