Subject: CVE-2024-46707: KVM: arm64: Make ICC_*SGI*_EL1 undef in the absence of a vGICv3

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

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

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

KVM: arm64: Make ICC_*SGI*_EL1 undef in the absence of a vGICv3

On a system with a GICv3, if a guest hasn't been configured with
GICv3 and that the host is not capable of GICv2 emulation,
a write to any of the ICC_*SGI*_EL1 registers is trapped to EL2.

We therefore try to emulate the SGI access, only to hit a NULL
pointer as no private interrupt is allocated (no GIC, remember?).

The obvious fix is to give the guest what it deserves, in the
shape of a UNDEF exception.

The Linux kernel CVE team has assigned CVE-2024-46707 to this issue.

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

	Fixed in 5.10.225 with commit 15818af2f7aa
	Fixed in 5.15.166 with commit 96b076e8ee5b
	Fixed in 6.1.107 with commit 94d4fbad01b1
	Fixed in 6.6.48 with commit 9d7629bec5c3
	Fixed in 6.10.7 with commit 2073132f6ed3
	Fixed in 6.11 with commit 3e6245ebe7ef

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-2024-46707
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/arm64/kvm/sys_regs.c
	arch/arm64/kvm/vgic/vgic.h

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/15818af2f7aa55eff375333cb7689df15d3f24ef
	https://git.kernel.org/stable/c/96b076e8ee5bc3a1126848c8add0f74bd30dc9d1
	https://git.kernel.org/stable/c/94d4fbad01b19ec5eab3d6b50aaec4f9db8b2d8d
	https://git.kernel.org/stable/c/9d7629bec5c3f80bd0e3bf8103c06a2f7046bd92
	https://git.kernel.org/stable/c/2073132f6ed3079369e857a8deb33d11bdd983bc
	https://git.kernel.org/stable/c/3e6245ebe7ef341639e9a7e402b3ade8ad45a19f