Bug 252222

Summary: ipv6 device reference counting error in net/ipv6/anycast.c
Product: Red Hat Enterprise Linux 4 Reporter: Charlotte Richardson <charlotte.richardson>
Component: kernelAssignee: Neil Horman <nhorman>
Status: CLOSED ERRATA QA Contact: Martin Jenner <mjenner>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.5CC: chas.horvath, jbaron, tgraf
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: RHSA-2008-0665 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2008-07-24 19:15:15 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: 430698    
Attachments:
Description Flags
backport of upstream patch none

Description Charlotte Richardson 2007-08-14 19:50:04 UTC 
Description of problem:
Reading /proc/net/anycast6 when there is no anycast address on an interface
results in an ever-increasing inet6_dev reference count, as well as a reference
to the netdevice you can't get rid of.

Version-Release number of selected component (if applicable):
2.6.9-55 kernel

How reproducible:
Every time

Steps to Reproduce:
1. cat /proc/net/anycast6
  
Actual results:
You will be unable to shutdown or reboot and will see console messages like
unregister_netdevice: waiting for eth<nnn> to become free. Usage count = 1

Expected results:
Nothing funky should happen.

Additional info:

This is due to a reference counting bug in net/ipv6/anycast.c. In static inline
struct ifacaddr *ac_get_first, after read_unlock_bh(&idev->lock); add
in6_dev_put(idev);

This source file is part of ipv6.ko.
Comment 1 Neil Horman 2007-08-28 16:48:01 UTC 
Created attachment 177081 [details]
backport of upstream patch

Thanks,backport of upstream commit aa6e4a96e7589948fe770744f7bb4f0f743dddaa
attached.
Comment 2 RHEL Program Management 2007-08-28 17:17:04 UTC 
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.
Comment 3 Jason Baron 2007-12-20 18:42:17 UTC 
committed in stream U7 build 68.4. A test kernel with this patch is available
from http://people.redhat.com/~jbaron/rhel4/
Comment 7 errata-xmlrpc 2008-07-24 19:15:15 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-2008-0665.html