Bug 1705498 (CVE-2019-11486)

Summary:	CVE-2019-11486 kernel: multiple race conditions in Siemens R3964 line discipline driver in drivers/tty/n_r3964.c leading to denial of service
Product:	[Other] Security Response	Reporter:	msiddiqu
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, airlied, bhu, blc, brdeoliv, bskeggs, dbaker, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jkacur, john.j5live, jonathan, josef, jross, jstancek, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, plougher, rt-maint, rvrbovsk, steved, williams, wmealing
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 5.0.8	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the Linux kernel's Siemens r3964 adapter driver. The flaw allows an attacker, with a local account and an ability to open the serial port of a Siemens r3964 adapter, may be able to abuse this race condition for memory corruption and possibly privilege escalation.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-05-31 06:19:46 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:	1705499
Bug Blocks:	1705500

Description msiddiqu 2019-05-02 12:15:13 UTC

The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel before 5.0.8 has multiple race conditions.

Upstream patch:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c7084edc3f6d67750f50d4183134c4fb5712a5c8 
https://github.com/torvalds/linux/commit/c7084edc3f6d67750f50d4183134c4fb5712a5c8

Reference:

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.8

Comment 1 msiddiqu 2019-05-02 12:15:49 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1705499]

Comment 2 Justin M. Forbes 2019-05-02 17:42:03 UTC

This was fixed for Fedora with the 5.0.8 stable kernel updates.

Comment 4 Wade Mealing 2019-05-31 05:45:02 UTC

The fix proposed by upstream is not actually fixing the problem, instead they are attempting to mask out the ability to build the code with the buggy implementation. The code with the race condition still exists in the repository, and likely other CVE's may come about if/when this driver gets fixed.

Comment 5 Wade Mealing 2019-05-31 05:52:10 UTC

Statement:
This task is marked as moderate as there is likely a chance for memory corruption, but this hardware is uncommon, it is unlikely that most systems have this hardware.