Bug 679080

Summary: fsck.gfs2: segfault in pass1b
Product: Red Hat Enterprise Linux 6 Reporter: Robert Peterson <rpeterso>
Component: clusterAssignee: Robert Peterson <rpeterso>
Status: CLOSED ERRATA QA Contact: Cluster QE <mspqa-list>
Severity: high Docs Contact:
Priority: medium    
Version: 6.1CC: ccaulfie, cluster-maint, djansa, edamato, fdinitto, jpayne, lhh, rpeterso, ssaha, swhiteho, teigland
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: cluster-3.0.12.1-2.el6 Doc Type: Bug Fix
Doc Text:
When fsck.gfs2 resolves duplicate block references, if all block references are found to be invalid (no valid references are found), its reference list becomes empty. Some code in pass1b improperly tried to access references on the empty list. As a result, fsck.gfs2 would end abnormally with a segmentation fault. Code was added to pass1b to check for the list being empty. As a result, the segmentation fault no longer occurs and fsck.gfs2 proceeds normally.
 Story Points: ---
Clone Of: 679076 Environment:
Last Closed: 2011-12-06 14:50:49 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: 679076    
Bug Blocks:    
Attachments:
Description Flags
Final patch none

Description Robert Peterson 2011-02-21 14:19:55 UTC 
+++ This bug was initially created as a clone of Bug #679076 +++
Cloned for a RHEL6 crosswrite fix.

Description of problem:
While recently analyzing a customer's gfs2 metadata, I ran
fsck.gfs2 and it segfaulted in pass1b.  I tracked down the
problem, and this bug is to track the problem and its fix.

Version-Release number of selected component (if applicable):
RHEL57

How reproducible:
Unknown

Steps to Reproduce:
1. Restore customer metadata
2. fsck.gfs2 -y /dev/device
3.
  
Actual results:
Segfault in pass1b

Expected results:
fsck.gfs2 should run to completion.

Additional info:
Patch available

--- Additional comment from rpeterso on 2011-02-21 09:15:25 EST ---

Created attachment 479925 [details]
Patch to fix the problem

The problem occurred when there were duplicate block
references in a dinode but all references in the duplicate
list are eventually deleted due to other corruption.
The fix is an additional check whether the list is empty.

--- Additional comment from rpeterso on 2011-02-21 09:16:28 EST ---

Requesting ack flags for 5.7.
Comment 1 Robert Peterson 2011-02-22 22:40:09 UTC 
I pushed the patch to the master branch of the gfs2-util
git repo.  I guess I'll have to wait to push it into the
RHEL6 branch of cluster.git until 6.1 branches from RHEL6,
unless management wants to squeeze it in.
Comment 2 Steve Whitehouse 2011-05-06 14:37:14 UTC 
Can we get this into the rhel6 branch yet?
Comment 3 Robert Peterson 2011-05-06 15:14:25 UTC 
RHEL61 still has not branched from RHEL6, so no.  I'll bug
Fabio when he's back from pto or Lon when he's back from Summit.
Comment 4 Robert Peterson 2011-06-03 12:55:35 UTC 
Created attachment 502805 [details]
Final patch

This is the patch I pushed to the cluster.git repo for the
RHEL6 branch.
Comment 5 Robert Peterson 2011-06-03 12:57:01 UTC 
Since the RHEL6 branch is now open for business, I pushed the
patch to it for inclusion into 6.2.  I tested it on system
gfs-i24c-01.  Changing status to POST until it gets built.
Comment 8 Robert Peterson 2011-10-27 13:49:57 UTC 
    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
When fsck.gfs2 resolves duplicate block references, if all block references are found to be invalid (no valid references are found), its reference list becomes empty.
Some code in pass1b improperly tried to access references on the empty list. As a result, fsck.gfs2 would end abnormally with a segmentation fault. Code was added to pass1b to check for the list being empty.  As a result, the segmentation fault no longer occurs and fsck.gfs2 proceeds normally.
Comment 9 Justin Payne 2011-11-08 17:10:37 UTC 
Verified SanityOnly in cluster-3.0.12.1-23.el6

https://brewweb.devel.redhat.com/buildinfo?buildID=181570
Comment 10 errata-xmlrpc 2011-12-06 14:50:49 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2011-1516.html