CVE-2026-89909: LoongArch: KVM: Free init resources if kvm_init() fails

CVE-2026-89909: LoongArch: KVM: Free init resources if kvm_init() fails

[Greg Kroah-Hartman]

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

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

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

LoongArch: KVM: Free init resources if kvm_init() fails

kvm_loongarch_init() calls kvm_loongarch_env_init() to allocate the
per-CPU kvm_context (vmcs) and kvm_loongarch_ops and to register the
perf callbacks, and then calls kvm_init(). If kvm_init() fails its
result is returned directly, but since module_init() does not run the
module_exit() stuff on failure, so kvm_loongarch_env_exit() is never
called and those resources are leaked.

So call kvm_loongarch_env_exit() when kvm_init() fails, matching the
teardown-on-failure pattern used by riscv_kvm_init().

The Linux kernel CVE team has assigned CVE-2026-89909 to this issue.


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

	Issue introduced in 6.7 with commit 2bd6ac68726131da32ace9717aa63ff68cf6605c and fixed in 6.12.110 with commit 6bbbd7b719233645a5c120557a9ca1422e6b7a48
	Issue introduced in 6.7 with commit 2bd6ac68726131da32ace9717aa63ff68cf6605c and fixed in 6.18.51 with commit 6b78786ee7260d9818cf1d7a245b7a655ef83076
	Issue introduced in 6.7 with commit 2bd6ac68726131da32ace9717aa63ff68cf6605c and fixed in 7.2.5 with commit 3bf6f5e2e1007d38a5f35bd37e94ab645a0c40bc
	Issue introduced in 6.7 with commit 2bd6ac68726131da32ace9717aa63ff68cf6605c and fixed in 7.3-rc2 with commit f7a1064cce3b100b54780c68529176232d8eb01e

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-2026-89909
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/main.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/6bbbd7b719233645a5c120557a9ca1422e6b7a48
	https://git.kernel.org/stable/c/6b78786ee7260d9818cf1d7a245b7a655ef83076
	https://git.kernel.org/stable/c/3bf6f5e2e1007d38a5f35bd37e94ab645a0c40bc
	https://git.kernel.org/stable/c/f7a1064cce3b100b54780c68529176232d8eb01e