Bug 190077

Summary: CVE-2006-2071 mprotect gives write permission to a readonly attachment
Product: Red Hat Enterprise Linux 2.1 Reporter: Marcel Holtmann <holtmann>
Component: kernelAssignee: Don Howard <dhoward>
Status: CLOSED ERRATA QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 2.1CC: security-response-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: ia64   
OS: Linux   
Whiteboard: impact=moderate,public=20060417
Fixed In Version: RHSA-2006-0580 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2006-07-13 11:55:45 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 143573    
Attachments:
Description Flags
Testcase for shmat/mprotect bug. Test should fail with -EPERM. none

Description Marcel Holtmann 2006-04-27 11:26:03 UTC 
All of 2.4 and 2.6 kernels have been letting mprotect give write permission to a
readonly attachment of shared memory, whether or not IPC would give the caller
that permission.

SUS says "The behaviour of this function [mprotect] is unspecified if the
mapping was not established by a call to mmap", but I don't think we can
interpret that as allowing it to subvert IPC permissions.
Comment 1 Marcel Holtmann 2006-04-27 11:32:07 UTC 
The upstream fix can be found here:

http://www.kernel.org/git/?p=linux/kernel/git/marcelo/linux-2.4.git;a=commit;h=0dba0f6b382bf360a1974fd78538273478dfc784
Comment 2 Marcel Holtmann 2006-04-27 17:25:40 UTC 
This is _not_ CVE-2006-1524. The commit message of the upstream fix is wrong.
Comment 5 Don Howard 2006-07-06 22:03:08 UTC 
Created attachment 132028 [details]
Testcase for shmat/mprotect bug.  Test should fail with -EPERM.
Comment 7 Mike Gahagan 2006-07-12 17:46:50 UTC 
Fix looks good:

.qa.[root@ia64-21as-bos root]# ./maywrite
shm segment attached at 0x300000
shmaddr)[512] =
mprotect() failed: Permission denied
.qa.[root@ia64-21as-bos root]# echo $?
1
Comment 9 Red Hat Bugzilla 2006-07-13 11:55:45 UTC 
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2006-0580.html