Bug 653254 - kernel: restrict unprivileged access to kernel syslog [mrg-2.1]
Summary: kernel: restrict unprivileged access to kernel syslog [mrg-2.1]
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise MRG
Classification: Red Hat
Component: realtime-kernel
Version: 2.0
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
: ---
Assignee: John Kacur
QA Contact: David Sommerseth
URL:
Whiteboard:
Depends On: 653245
Blocks: 653250 653252
TreeView+ depends on / blocked
 
Reported: 2010-11-15 04:31 UTC by Eugene Teo (Security Response)
Modified: 2016-05-22 23:31 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 653245
Environment:
Last Closed: 2014-09-25 20:06:41 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)

Description Eugene Teo (Security Response) 2010-11-15 04:31:45 UTC 
+++ This bug was initially created as a clone of Bug #653245 +++

Description of problem:
The kernel syslog contains debugging information that is often useful during exploitation of other vulnerabilities, such as kernel heap addresses.  Rather than futilely attempt to sanitize hundreds (or thousands) of printk statements and simultaneously cripple useful debugging functionality, it is far simpler to create an option that prevents unprivileged users from reading the syslog.
    
This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the dmesg_restrict sysctl.  When set to "0", the default, no restrictions are enforced.  When set to "1", only users with CAP_SYS_ADMIN can read the kernel syslog via dmesg(8) or other mechanisms.

Upstream commit:
http://git.kernel.org/linus/eaf06b241b091357e72b76863ba16e89610d31bd
Comment 1 Eugene Teo (Security Response) 2011-06-02 09:10:00 UTC 
mv 1.3 to 2.0
Comment 2 Eugene Teo (Security Response) 2011-10-03 04:57:44 UTC 
The patch is in rt-3.0.4-rt14 as far as I can see.
Comment 5 Beth Uptagrafft 2014-09-25 20:06:41 UTC 
The patch was in rt-3.0.4-rt14
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