Bug 1824803 (CVE-2020-11669) - CVE-2020-11669 kernel: powerpc: guest can cause DoS on POWER9 KVM hosts
Summary: CVE-2020-11669 kernel: powerpc: guest can cause DoS on POWER9 KVM hosts
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2020-11669
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1824804 1829045
Blocks: 1824733
TreeView+ depends on / blocked
 
Reported: 2020-04-16 13:21 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-04-27 10:46 UTC (History)
43 users (show)

Fixed In Version: kernel-5.2
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the way Linux kernel running on the Power9 processor saves and restores its registers while going in and coming out of an idle state. The issue occurs when a guest kernel has Kernel Userspace Address Protection (KUAP) feature enabled. The idle_book3s function does not save and restore the Authority Mask Register (AMR), Authority Mask Override Register (AMOR) and User Authority Mask Override Register (UAMOR). A guest user may use this flaw to render the host system unusable resulting in DoS issue.
Clone Of:
Environment:
Last Closed: 2021-04-27 10:46:31 UTC
Embargoed:

Attachments (Terms of Use)

Description Guilherme de Almeida Suckevicz 2020-04-16 13:21:39 UTC 
A flaw was found in the way Linux kernel running on the Power9 processor saves and restores its registers while going in and coming out of an idle state. The issue occurs when a guest kernel has Kernel Userspace Address Protection (KUAP) feature enabled. The idle_book3s function does not save and restore the Authority Mask Register (AMR), Authority Mask Override Register (AMOR) and User Authority Mask Override Register (UAMOR). A guest user may use this flaw to render the host system unusable resulting in DoS issue.


Upstream commit:
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  -> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=53a712bae5dd919521a58d7bad773b949358add0

Reference:
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  -> http://www.openwall.com/lists/oss-security/2020/04/15/1
Comment 1 Guilherme de Almeida Suckevicz 2020-04-16 13:23:02 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1824804]
Comment 2 Justin M. Forbes 2020-04-16 13:39:09 UTC 
This was fixed for Fedora with the 5.0.17 stable kernel updates.
Comment 6 Prasad Pandit 2020-05-04 09:03:49 UTC 
Statement:

This issue does not affect the versions of the kernel package as shipped with the Red Hat Enterprise Linux 5, 6, 7, 8 and Red Hat Enterprise MRG 2.
Comment 9 errata-xmlrpc 2021-04-27 07:21:05 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2021:1379 https://access.redhat.com/errata/RHSA-2021:1379
Comment 10 Product Security DevOps Team 2021-04-27 10:46:31 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-2020-11669
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