834596 – (CVE-2021-3638) app-emulation/qemu: DoS via guest in ATI VGA emulation

Bug 834596 (CVE-2021-3638) - app-emulation/qemu: DoS via guest in ATI VGA emulation

Summary: app-emulation/qemu: DoS via guest in ATI VGA emulation

Status:	RESOLVED INVALID

Alias:	CVE-2021-3638

Product:	Gentoo Security
Classification:	Unclassified
Component:	Vulnerabilities (show other bugs)
Hardware:	All Linux

Importance:	Normal minor
Assignee:	Gentoo Security

URL:	https://bugzilla.redhat.com/show_bug....
Whiteboard:	B3 [upstream]
Keywords:

Depends on:
Blocks:

Reported:	2022-03-05 03:49 UTC by John Helmert III
Modified:	2022-03-05 03:52 UTC (History)
CC List:	4 users (show)

See Also:
Package list:
Runtime testing required:	---

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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