Bug 2037790 (CVE-2022-0135)

Summary:	CVE-2022-0135 virglrenderer: out-of-bounds write in read_transfer_data()
Product:	[Other] Security Response	Reporter:	Michael Kaplan <mkaplan>
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:	An out-of-bounds write issue was found in the VirGL virtual OpenGL renderer (virglrenderer). This flaw allows a malicious guest to create a specially crafted virgil resource and then issue a VIRTGPU_EXECBUFFER ioctl, leading to a denial of service or possible code execution.	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:	2048607, 2048612, 2048606, 2048613
Bug Blocks:	2037791, 2037795

Description Michael Kaplan 2022-01-06 15:24:29 UTC

An out-of-bound write was found in virglrenderer in src/vrend_renderer.c:read_transfer_data().

Comment 1 Mauro Matteo Cascella 2022-01-31 15:06:50 UTC

Upstream commit:
https://gitlab.freedesktop.org/virgl/virglrenderer/-/commit/95e581fd181b213c2ed7cdc63f2abc03eaaa77ec

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

Comment 2 Mauro Matteo Cascella 2022-01-31 15:35:22 UTC

Created virglrenderer tracking bugs for this issue:

Affects: epel-8 [bug 2048607]
Affects: fedora-all [bug 2048606]

Comment 5 Mauro Matteo Cascella 2022-01-31 17:35:34 UTC

The flaw arises from the fact that both vrend_renderer_transfer_write_iov() and read_transfer_data() calculate `send_size` to allocate a buffer and transfer data to it, respectively. However, they calculate the size in a slightly different way: vrend_renderer_transfer_write_iov() does not take `box->depth` into account. Under certain circumstances, this could lead to the allocation of a smaller heap buffer which is later accessed out-of-bounds by read_transfer_data.