CVE-2026-72295: LoongArch: KVM: Validate irqchip index in irqfd routing

CVE-2026-72295: LoongArch: KVM: Validate irqchip index in irqfd routing

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

LoongArch: KVM: Validate irqchip index in irqfd routing

Sashiko reported that the irqchip index is not validated for LoongArch.
Add validation and reject out-of-range irqchip indexes to avoid indexing
past the routing table's chip array.

The Linux kernel CVE team has assigned CVE-2026-72295 to this issue.


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

	Issue introduced in 6.13 with commit 1928254c5ccb7bdffd7f0334e1ce250e9ce4de94 and fixed in 6.18.40 with commit 199b570d7fca1aa70e596f10a6276997becffb6d
	Issue introduced in 6.13 with commit 1928254c5ccb7bdffd7f0334e1ce250e9ce4de94 and fixed in 7.1.5 with commit 8b3e188d19e4ffe916780aeb7ddad9d6457b8bcc
	Issue introduced in 6.13 with commit 1928254c5ccb7bdffd7f0334e1ce250e9ce4de94 and fixed in 7.2-rc1 with commit 3474037904c20ff915e3ebab0ab5c1e41bbe549e

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-2026-72295
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:
	arch/loongarch/kvm/irqfd.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/199b570d7fca1aa70e596f10a6276997becffb6d
	https://git.kernel.org/stable/c/8b3e188d19e4ffe916780aeb7ddad9d6457b8bcc
	https://git.kernel.org/stable/c/3474037904c20ff915e3ebab0ab5c1e41bbe549e