CVE-2024-42230 Information

Description

In the Linux kernel the following vulnerability has been resolved:

powerpc/pseries: Fix scv instruction crash with kexec

kexec on pseries disables AIL (reloc_on_exc) required for scv instruction support before other CPUs have been shut down. This means they can execute scv instructions after AIL is disabled which causes an interrupt at an unexpected entry location that crashes the kernel.

Change the kexec sequence to disable AIL after other CPUs have been brought down.

As a refresher the real-mode scv interrupt vector is 0x17000 and the fixed-location head code probably couldn’t easily deal with implementing such high addresses so it was just decided not to support that interrupt at all.

Reference

https://git.kernel.org/stable/c/c550679d604798d9fed8a5b2bb5693448a25407c https://git.kernel.org/stable/c/d10e3c39001e9194b9a1bfd6979bd3fa19dccdc5 https://git.kernel.org/stable/c/8c6506616386ce37e59b2745fc481c6713fae4f3 https://git.kernel.org/stable/c/21a741eb75f80397e5f7d3739e24d7d75e619011