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Bug 511185

Summary: kernel: build with -fno-delete-null-pointer-checks [rhel-3]
Product: Red Hat Enterprise Linux 3 Reporter: Eugene Teo (Security Response) <eteo>
Component: kernelAssignee: Don Howard <dhoward>
Status: CLOSED ERRATA QA Contact: Martin Jenner <mjenner>
Severity: high Docs Contact:
Priority: urgent    
Version: 3.9CC: dhoward, lwang
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: 511181 Environment:
Last Closed: 2009-11-03 22:00:26 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: 511181    
Bug Blocks:    

Description Eugene Teo (Security Response) 2009-07-14 04:37:45 UTC 
+++ This bug was initially created as a clone of Bug #511181 +++

Description of problem:
http://gcc.gnu.org/onlinedocs/gcc-3.2.3/gcc/Optimize-Options.html

-fdelete-null-pointer-checks
    Use global dataflow analysis to identify and eliminate useless checks for null pointers. The compiler assumes that dereferencing a null pointer would have halted the program. If a pointer is checked after it has already been dereferenced, it cannot be null.

    In some environments, this assumption is not true, and programs can safely dereference null pointers. Use -fno-delete-null-pointer-checks to disable this optimization for programs which depend on that behavior.

    Enabled at levels -O2, -O3, -Os.
Comment 2 Eugene Teo (Security Response) 2009-07-17 00:23:33 UTC 
Upstream commit:
http://git.kernel.org/linus/a3ca86aea507904148870946d599e07a340b39bf
Comment 3 Eugene Teo (Security Response) 2009-07-20 09:52:04 UTC 
Upstream 2.4 commit:
http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.4.37.y.git;a=commit;h=c23e12166a48df3c8a36a8263f37f5da8928e6b5
Comment 5 Don Howard 2009-10-16 18:50:02 UTC 
A patch for this issue has been included in build 2.4.21-61.EL.
Comment 9 errata-xmlrpc 2009-11-03 22:00:26 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 therefore 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-2009-1550.html