Subject: CVE-2024-36913: Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails

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

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

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

Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails

In CoCo VMs it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.

VMBus code could free decrypted pages if set_memory_encrypted()/decrypted()
fails. Leak the pages if this happens.

The Linux kernel CVE team has assigned CVE-2024-36913 to this issue.

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

	Fixed in 6.6.31 with commit 6123a4e8e25b
	Fixed in 6.8.10 with commit e813a0fc2e59
	Fixed in 6.9 with commit 03f5a999adba

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-2024-36913
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/hv/connection.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/6123a4e8e25bd40cf44db14694abac00e6b664e6
	https://git.kernel.org/stable/c/e813a0fc2e597146e9cebea61ced9c796d4e308f
	https://git.kernel.org/stable/c/03f5a999adba062456c8c818a683beb1b498983a