Bug 1899985 (CVE-2020-28941)

Summary:	CVE-2020-28941 kernel: NULL pointer dereference in spk_ttyio_ldisc_close function in drivers/accessibility/speakup/spk_ttyio.c
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, bhu, blc, bmasney, brdeoliv, bskeggs, darunesh, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, jonathan, josef, jross, jshortt, jstancek, jwboyer, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, mchehab, mcressma, mjg59, mlangsdo, nmurray, pmatouse, ptalbert, qzhao, rt-maint, rvrbovsk, steved, walters, 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:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-11-26 15:05:02 UTC	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:	1899986
Bug Blocks:	1896726

Description Guilherme de Almeida Suckevicz 2020-11-20 14:31:34 UTC

An issue was discovered in drivers/accessibility/speakup/spk_ttyio.c in the Linux kernel through 5.9.9. Local attackers on systems with the speakup driver could cause a local denial of service attack. This occurs because of an invalid free when the line discipline is used more than once.

References:
https://www.openwall.com/lists/oss-security/2020/11/19/3
http://www.openwall.com/lists/oss-security/2020/11/19/5

Upstream patch:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d4122754442799187d5d537a9c039a49a67e57f1

Comment 1 Guilherme de Almeida Suckevicz 2020-11-20 14:32:13 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1899986]

Comment 2 Dhananjay Arunesh 2020-11-25 20:57:37 UTC

*** Bug 1901723 has been marked as a duplicate of this bug. ***