Bug 470758 - kernel: file caps: always start with clear bprm->caps_*
Summary: kernel: file caps: always start with clear bprm->caps_*
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 470759
Blocks:
TreeView+ depends on / blocked
 
Reported: 2008-11-10 03:38 UTC by Eugene Teo (Security Response)
Modified: 2011-09-30 20:59 UTC (History)
4 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2011-09-30 20:59:16 UTC
Embargoed:

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Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2009:0053 0 normal SHIPPED_LIVE Important: kernel-rt security and bug fix update 2009-02-04 15:05:12 UTC

Description Eugene Teo (Security Response) 2008-11-10 03:38:37 UTC 
Description of problem:
From: Serge Hallyn <serue.com>

While Linux doesn't honor setuid on scripts.  However, it mistakenly
behaves differently for file capabilities.

This patch fixes that behavior by making sure that get_file_caps()
begins with empty bprm->caps_*.  That way when a script is loaded,
its bprm->caps_* may be filled when binfmt_misc calls prepare_binprm(),
but they will be cleared again when binfmt_elf calls prepare_binprm()
next to read the interpreter's file capabilities.
Comment 1 Eugene Teo (Security Response) 2008-11-10 03:39:21 UTC 
Proposed upstream patch:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3318a386e4ca68c76e0294363d29bdc46fcad670
Comment 4 Kurt Seifried 2011-09-30 20:59:16 UTC 
This issue has been addressed in following products:

  Red Hat Enterprise MRG v1 for Red Hat Enterprise Linux (version 5)
  
Via RHSA-2009:0053 available at https://rhn.redhat.com/errata/RHSA-2009-0053.html
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