Bug 1777825 (CVE-2019-18660)

Summary: CVE-2019-18660 kernel: (powerpc) incomplete Spectre-RSB mitigation leads to information exposure
Product: [Other] Security Response Reporter: msiddiqu
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: acaringi, airlied, bdettelb, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hannsj_uhl, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, john.j5live, jonathan, josef, jross, jschorr, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, plougher, ppandit, qzhao, rt-maint, rvrbovsk, security-response-team, steved, tumeya, williams
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
A flaw was found in the way the Linux kernel implemented a software flush of the Count Cache (indirect branch cache) and Link (Return Address) Stack on the PowerPC platform. The flushing of these structures helps to prevent SpectreRSB like attacks which may leak information from one user process to another. An unprivileged user could use this flaw to cross the syscall or process boundary and read privileged memory by conducting targeted cache side-channel attacks.
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-01-21 20:10:02 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 1777686, 1777710, 1793856, 1777826, 1778342    
Bug Blocks: 1777827    

Description msiddiqu 2019-11-28 12:06:13 UTC
An issue was found in the way Linux kernel implemented software flush of the Count Cache (indirect branch cache) and Link (Return Address) Stack on PowerPC platform. The flushing of these structures helps to prevent SpectreRSB like attacks which may leak information from one user process to another.

An unprivileged user could use this flaw to cross the syscall or process boundary and read privileged memory by conducting targeted cache side-channel attacks.

Upstream commit: 
----------------
  -> https://git.kernel.org/linus/39e72bf96f5847ba87cc5bd7a3ce0fed813dc9ad
  -> https://git.kernel.org/linus/af2e8c68b9c5403f77096969c516f742f5bb29e0

References:
-----------
  -> https://www.openwall.com/lists/oss-security/2019/11/27/1

Comment 1 msiddiqu 2019-11-28 12:06:45 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1777826]

Comment 5 errata-xmlrpc 2020-01-21 15:50:13 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:0174 https://access.redhat.com/errata/RHSA-2020:0174

Comment 6 Product Security DevOps Team 2020-01-21 20:10:02 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2019-18660

Comment 8 Prasad J Pandit 2020-01-22 07:06:49 UTC
Statement:

This issue affects versions of the kernel package as shipped with Red Hat Enterprise Linux 6, 7 and 8. Future kernel updates for Red Hat Enterprise Linux 6, 7 and 8 may address this issue.

This issue does not affect the version of the kernel package as shipped with Red Hat Enterprise MRG 2.