Bug 1349916 (CVE-2016-5412)

Summary: CVE-2016-5412 Kernel: powerpc: kvm: Infinite loop via H_CEDE hypercall when running under hypervisor-mode
Product: [Other] Security Response Reporter: Adam Mariš <amaris>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: ailan, alonbl, apevec, areis, ayoung, bmcclain, chrisw, cvsbot-xmlrpc, dblechte, drjones, eedri, imammedo, jen, jschluet, kbasil, knoel, lhh, lpeer, markmc, mgoldboi, michal.skrivanek, mkenneth, mrezanin, mst, pbonzini, ppandit, qzhang, rbryant, rkrcmar, sclewis, security-response-team, srevivo, tdecacqu, vkuznets, xuhan, ykaul
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Clone Of: Environment:
Last Closed: 2019-06-08 02:55:50 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: 1349244, 1360798, 1361040    
Bug Blocks: 1348800    
Attachments:
Description Flags
Patch 1
none
Patch 2 none

Description Adam Mariš 2016-06-24 14:21:14 UTC 
It was reported that when a guest kernel running under hypervisor-mode KVM (i.e. "HV KVM" rather than "PR KVM"), does the H_CEDE hypercall while a suspended transaction exists, the host CPU may, under certain circumstances, hang in an infinite loop with interrupts disabled. To trigger this, it is necessary to have the guest using an SMT mode of at least 2, with another thread in the same core busy at the time that the H_CEDE is done. The other thread doesn't need to be using transactional memory.

Upstream patches:
-----------------
  -> https://marc.info/?l=kvm&m=146968629127349&w=2
Comment 2 Adam Mariš 2016-06-24 14:36:21 UTC 
Created attachment 1171980 [details]
Patch 1
Comment 3 Adam Mariš 2016-06-24 14:36:52 UTC 
Created attachment 1171981 [details]
Patch 2
Comment 5 Prasad Pandit 2016-07-28 08:39:47 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1361040]
Comment 6 Prasad Pandit 2016-07-28 11:34:06 UTC 
Statement:

This issue does not affect the versions of Linux kernel as shipped with
Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG 2.

This issue affects the version of the kernel packages as shipped with
Red Hat Enterprise Linux 7. Future kernel updates for Red Hat Enterprise Linux 7 may address this issue.
Comment 10 Fedora Update System 2016-08-15 21:23:28 UTC 
kernel-4.6.6-300.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.
Comment 11 Fedora Update System 2016-08-16 00:50:18 UTC 
kernel-4.6.6-200.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.
Comment 15 errata-xmlrpc 2016-11-03 16:45:00 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2574 https://rhn.redhat.com/errata/RHSA-2016-2574.html
Comment 16 errata-xmlrpc 2016-11-03 21:35:37 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2574 https://rhn.redhat.com/errata/RHSA-2016-2574.html