Bug 1876995 (CVE-2020-25639)

Summary:	CVE-2020-25639 kernel: NULL pointer dereference via nouveau ioctl can lead to DoS
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	acaringi, airlied, bhu, blc, bmasney, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jlelli, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, kherbst, lgoncalv, linville, masami256, mchehab, mcressma, mjg59, mlangsdo, nmurray, ptalbert, qzhao, rt-maint, rvrbovsk, security-response-team, steved, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Linux kernel 5.12-rc1	Doc Type:	If docs needed, set a value
Doc Text:	A NULL pointer dereference flaw was found in the Linux kernel’s GPU Nouveau driver functionality in the way the user calls ioctl DRM_IOCTL_NOUVEAU_CHANNEL_ALLOC. This flaw allows a local user to crash the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-11-07 11:23:48 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Bug Depends On:	1935209, 1877471, 1877472, 1881465, 1911194
Bug Blocks:	1873622

Description Guilherme de Almeida Suckevicz 2020-09-08 16:51:13 UTC

A flaw was found in the Linux kernel where an unprivileged console user can crash kernel via a nouveau ioctl.

Reference:
https://lists.freedesktop.org/archives/nouveau/2020-August/036682.html

Comment 4 Alex 2020-09-21 20:07:32 UTC

Acknowledgments:

Name: Frantisek Hrbata (Red Hat)

Comment 6 Alex 2020-09-22 13:10:08 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1881465]

Comment 7 RaTasha Tillery-Smith 2020-09-29 19:41:49 UTC

Statement:

This flaw is rated as having a Low impact because the issue can only be triggered by an authorized local user in the render group.

Comment 10 Alex 2020-12-09 16:34:48 UTC

Mitigation:

To mitigate this issue, prevent the module nouveau from being loaded. Please see https://access.redhat.com/solutions/41278 for information on how to blacklist a kernel module to prevent it from loading automatically.

Comment 25 Karol Herbst 2021-10-26 15:10:40 UTC

Fixed upstream with eaba3b28401f5

Comment 26 Alex 2021-11-07 11:23:48 UTC

Before closing, checked that for the rhel-9 already applied.