Bug 834596 (CVE-2021-3638)

Summary:	app-emulation/qemu: DoS via guest in ATI VGA emulation
Product:	Gentoo Security	Reporter:	John Helmert III <ajak>
Component:	Vulnerabilities	Assignee:	Gentoo Security <security>
Status:	RESOLVED INVALID
Severity:	minor	CC:	ajak, tamiko, virtualization, zlogene
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://bugzilla.redhat.com/show_bug.cgi?id=1979858
Whiteboard:	B3 [upstream]
Package list:		Runtime testing required:	---

Description John Helmert III archtester

2022-03-05 03:49:55 UTC

CVE-2021-3638:

An out-of-bounds memory access flaw was found in the ATI VGA device emulation of QEMU. This flaw occurs in the ati_2d_blt() routine while handling MMIO write operations when the guest provides invalid values for the destination display parameters. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service.

Only real reference is Redhat's bug, unmerged patch is here:
https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg01682.html

Comment 1 John Helmert III archtester

2022-03-05 03:52:43 UTC

.. though, upstream seems to think this isn't a real security bug since ati-vga is clearly experimental.

https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg02544.html