Subject: CVE-2024-35800: efi: fix panic in kdump kernel

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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

efi: fix panic in kdump kernel

Check if get_next_variable() is actually valid pointer before
calling it. In kdump kernel this method is set to NULL that causes
panic during the kexec-ed kernel boot.

Tested with QEMU and OVMF firmware.

The Linux kernel CVE team has assigned CVE-2024-35800 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 6.1.81 with commit a8901f331b8b and fixed in 6.1.84 with commit b9d103aca85f
	Issue introduced in 6.3 with commit bad267f9e18f and fixed in 6.6.24 with commit 9114ba998750
	Issue introduced in 6.3 with commit bad267f9e18f and fixed in 6.7.12 with commit 7784135f134c
	Issue introduced in 6.3 with commit bad267f9e18f and fixed in 6.8.3 with commit 090d2b4515ad
	Issue introduced in 6.3 with commit bad267f9e18f and fixed in 6.9 with commit 62b71cd73d41

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-35800
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/firmware/efi/efi.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/b9d103aca85f082a343b222493f3cab1219aaaf4
	https://git.kernel.org/stable/c/9114ba9987506bcfbb454f6e68558d68cb1abbde
	https://git.kernel.org/stable/c/7784135f134c13af17d9ffb39a57db8500bc60ff
	https://git.kernel.org/stable/c/090d2b4515ade379cd592fbc8931344945978210
	https://git.kernel.org/stable/c/62b71cd73d41ddac6b1760402bbe8c4932e23531