Bug 1256399 (CVE-2015-6654, xsa141) - CVE-2015-6654 xen: printk is not rate-limited in xenmem_add_to_physmap_one
Summary: CVE-2015-6654 xen: printk is not rate-limited in xenmem_add_to_physmap_one
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2015-6654, xsa141
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks: 1256401
TreeView+ depends on / blocked
 
Reported: 2015-08-24 13:20 UTC by Adam Mariš
Modified: 2021-02-17 04:59 UTC (History)
10 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2015-08-26 11:09:54 UTC


Attachments (Terms of Use)
xsa141 patch (1.03 KB, patch)
2015-08-24 13:24 UTC, Adam Mariš
no flags Details | Diff

Description Adam Mariš 2015-08-24 13:20:40 UTC
XENMAPSPACE_gmfn_foreign dumps the p2m, on ARM, when it fails to get a
reference on the foreign page. However, dump_p2m_lookup does not use
rate-limited printk.

A malicious infrastructure domain, which is allowed to map memory of
a foreign guest, would be able to flood the Xen console.

Impact:

Domains deliberately given partial management control may be able to
deny service to other parts of the system.

As a result, in a system designed to enhance security by radically
disaggregating the management, the security may be reduced. But, the
security will be no worse than a non-disaggregated design.

Vulnerable systems:

This issue is only relevant to systems which intend to increase
security through the use of advanced disaggregated management
techniques.

This does not include systems using libxl, libvirt, xm/xend,
XCP/XenServer, OpenStack or CloudStack (unless substantially modified
or supplemented, as compared to versions supplied by the respective
upstreams).

This issue is not relevant to stub device models, driver domains, or
stub xenstored. Those disaggregation techniques do not rely on
granting the semi-privileged support domains access to the affected
hypercall, and are believed to provide the intended security benefits.

Only ARM systems are potentially affected. All Xen versions which
support ARM are potentially affected.

Comment 1 Adam Mariš 2015-08-24 13:24:27 UTC
Created attachment 1066392 [details]
xsa141 patch

Comment 2 Petr Matousek 2015-08-26 11:09:54 UTC
Statement:

Not vulnerable.

This issue does not affect the Xen hypervisor packages as shipped with Red Hat Enterprise Linux 5.

This issue does not affect Red Hat Enterprise Linux 6, 7 or any other Red Hat supported product because of the lack of Xen hypervisor support.


Note You need to log in before you can comment on or make changes to this bug.