Bug 1752081 (CVE-2019-15902)

Summary:	CVE-2019-15902 kernel: backporting error in ptrace_get_debugreg()
Product:	[Other] Security Response	Reporter:	Dhananjay Arunesh <darunesh>
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, airlied, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, plougher, rt-maint, rvrbovsk, steved, williams, yozone
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:	2019-09-17 13:39:17 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:	1752085
Bug Blocks:	1752084

Description Dhananjay Arunesh 2019-09-13 16:45:12 UTC

A backporting error was discovered in the Linux stable/longterm kernel. Misuse of the upstream "x86/ptrace: Fix possible spectre-v1 in ptrace_get_debugreg()" commit reintroduced the Spectre vulnerability that it aimed to eliminate. This occurred because the backport process depends on cherry picking specific commits, and because two (correctly ordered) code lines were swapped.

Reference:
https://grsecurity.net/teardown_of_a_failed_linux_lts_spectre_fix.php

Comment 1 Dhananjay Arunesh 2019-09-13 16:48:16 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1752085]

Comment 2 Justin M. Forbes 2019-09-16 12:18:31 UTC

This is fixed for Fedora with the 5.2.12 stable kernel updates.