Bug 377561 (CVE-2007-5907) - CVE-2007-5907 kernel-xen 3.1.1 does not prevent modification of the CR4 TSC from applications (DoS possible)
Summary: CVE-2007-5907 kernel-xen 3.1.1 does not prevent modification of the CR4 TSC f...
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: CVE-2007-5907
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Chris Lalancette
QA Contact:
URL:
Whiteboard:
Depends On: 378471 378481 390091 390101 390111 390121
Blocks: 470954
TreeView+ depends on / blocked
 
Reported: 2007-11-12 11:21 UTC by Jan Lieskovsky
Modified: 2019-09-29 12:22 UTC (History)
9 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2009-08-25 10:24:00 UTC
Embargoed:


Attachments (Terms of Use)
Patch to allow guest kernels to trap CR4 access (19.54 KB, patch)
2008-09-12 14:13 UTC, Chris Lalancette
no flags Details | Diff


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2008:0957 0 normal SHIPPED_LIVE Important: kernel security and bug fix update 2008-11-12 09:34:44 UTC

Description Jan Lieskovsky 2007-11-12 11:21:09 UTC
Description of problem:

Xen 3.1.1 does not prevent modification of the CR4 TSC from
applications, which allows pv guests to cause a denial of service
(crash). (CVE-2007-5907).

Comment 3 Jan Lieskovsky 2007-11-16 14:59:27 UTC
The official post is here -- there is also patch provided: 
 
http://lists.xensource.com/archives/html/xen-devel/2007-10/msg00932.html 

Comment 11 Chris Lalancette 2008-09-12 14:13:05 UTC
Created attachment 316578 [details]
Patch to allow guest kernels to trap CR4 access

This is the current patch I've been testing for this issue.  It's pretty close to xen-unstable c/s 16259 + 16333, but has the following modifications:

1)  irq_masked() is called in a few different places in the 3.1 codebase, so fix up all of the callers of it.
2)  Remove all calls to pge_off and pge_on.  Upstream went with a re-written flushing mechanism before this c/s went in, so just make sure to follow the pge_off/pge_on discipline that was there.

Chris Lalancette

Comment 12 Chris Lalancette 2008-09-16 09:46:59 UTC
Comment on attachment 316578 [details]
Patch to allow guest kernels to trap CR4 access

Since this is the master tracking bug, this patch doesn't belong here.  Obsoleting.


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