Subject: CVE-2021-47296: KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leak

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

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

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

KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leak

vcpu_put is not called if the user copy fails. This can result in preempt
notifier corruption and crashes, among other issues.

The Linux kernel CVE team has assigned CVE-2021-47296 to this issue.

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

	Issue introduced in 4.18 with commit b3cebfe8c1ca and fixed in 4.19.199 with commit 9bafc34dc4ad
	Issue introduced in 4.18 with commit b3cebfe8c1ca and fixed in 5.4.136 with commit f38527f18905
	Issue introduced in 4.18 with commit b3cebfe8c1ca and fixed in 5.10.54 with commit e14ef1095387
	Issue introduced in 4.18 with commit b3cebfe8c1ca and fixed in 5.13.6 with commit a4a488915fea
	Issue introduced in 4.18 with commit b3cebfe8c1ca and fixed in 5.14 with commit bc4188a2f56e

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-2021-47296
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/powerpc/kvm/powerpc.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/9bafc34dc4ad0cef18727c557f21ed3c3304df50
	https://git.kernel.org/stable/c/f38527f1890543cdfca8dfd06f75f9887cce6151
	https://git.kernel.org/stable/c/e14ef1095387f764d95614d3ec9e4d07c82a3533
	https://git.kernel.org/stable/c/a4a488915feaad38345cc01b80d52e8200ff5209
	https://git.kernel.org/stable/c/bc4188a2f56e821ea057aca6bf444e138d06c252