Bug 1972265 (CVE-2021-34693)

Summary:	CVE-2021-34693 kernel: allows local users to obtain sensitive information from stack memory because of uninitialized data structure in net/can/bcm.c
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bhu, blc, chwhite, crwood, dvlasenk, hdegoede, hkrzesin, jarod, jarodwilson, jeremy, jforbes, jlelli, jonathan, josef, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mlangsdo, nmurray, ptalbert, qzhao, rvrbovsk, steved, walters, wcosta, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	The canbus filesystem in the Linux kernel contains an information leak of kernel memory to devices on the CAN bus network link layer. An attacker with the ability to dump messages on the CAN bus is able to learn of uninitialized stack values by dumbing messages on the can bus.	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:	1972267, 1973498, 1973499, 1973500, 1986334
Bug Blocks:	1972269

Description Guilherme de Almeida Suckevicz 2021-06-15 14:34:32 UTC

The canbus filesystem in the Linux kernel contains an information leak of kernel memory to devices on the CAN bus network link layer.  An attacker with the ability to dump messages on the CAN bus is able to learn of uninitialized stack values by dumbing messages on the can bus.

Reference:
https://lore.kernel.org/netdev/trinity-87eaea25-2a7d-4aa9-92a5-269b822e5d95-1623609211076@3c-app-gmx-bs04/T/

Comment 1 Guilherme de Almeida Suckevicz 2021-06-15 14:35:14 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1972267]

Comment 6 Justin M. Forbes 2021-06-29 16:27:24 UTC

This was fixed for Fedora with the 5.12.13 stable kernel updates.