Bug 2039003 (CVE-2022-0175)

Summary:	CVE-2022-0175 virglrenderer: memory initialization issue in vrend_resource_alloc_buffer() can lead to info leak
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	airlied, marcandre.lureau, virt-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the VirGL virtual OpenGL renderer (virglrenderer). The virgl did not properly initialize memory when allocating a host-backed memory resource. A malicious guest could use this flaw to mmap from the guest kernel and read this uninitialized memory from the host, possibly leading to information disclosure.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2039343, 2039342, 2048503, 2048504
Bug Blocks:	2039004, 2039007

Description Pedro Sampaio 2022-01-10 17:52:24 UTC

The virgl forgets to initialize the memory pointed by the res->ptr when it
creates resource. And the memory can be mapped to the guest kernel when the
VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING is issued. However, the guest
userspace can read the data in the unintialized host memory by mmaping it
from the guest kernel.

Upstream fix:

https://gitlab.freedesktop.org/virgl/virglrenderer/-/commit/b05bb61f454eeb8a85164c8a31510aeb9d79129c

Comment 1 Pedro Sampaio 2022-01-11 14:22:42 UTC

Created virglrenderer tracking bugs for this issue:

Affects: epel-8 [bug 2039343]
Affects: fedora-all [bug 2039342]

Comment 2 Mauro Matteo Cascella 2022-01-31 11:43:25 UTC

Upstream MR:
https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/654