Bug 524884

Summary: reading from /proc/net/ip_conntrack returns ENOSPC
Product: Red Hat Enterprise Linux 4 Reporter: Marc Milgram <mmilgram>
Component: kernelAssignee: Danny Feng <dfeng>
Status: CLOSED ERRATA QA Contact: Dayong Tian <dtian>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.9CC: dtian
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-02-16 15:57:52 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:
Attachments:
Description Flags
posted patch none

Description Marc Milgram 2009-09-22 15:23:11 UTC 
Description of problem:
If the hash chain is too long, reading from /proc/net/ip_conntrack doesn't doesn't output useful data, but instead outputs "No space left on device"

Version-Release number of selected component (if applicable):
kernel-2.6.9-78.0.13.ELsmp

How reproducible:
Always

Steps to Reproduce:
1. iptables rules to track the connection
2. incoming load
3. cat or wc on /proc/net/ip_conntrack
  
Actual results:
cat or wc results in End of space message

Expected results:
Read to /proc/net/ip_conntrack should not fail or throw the error message

Additional info:
Comment 1 Marc Milgram 2009-09-22 15:24:16 UTC 
It looks like this is the piece of code that is responsible for this message

static int ct_seq_show(struct seq_file *s, void *v)
{
       struct list_head *list = v;
       int ret = 0;

       /* FIXME: Simply truncates if hash chain too long. */
       READ_LOCK(&ip_conntrack_lock);
       if (LIST_FIND(list, ct_seq_real_show,
                     struct ip_conntrack_tuple_hash *, s))
               ret = -ENOSPC;
       READ_UNLOCK(&ip_conntrack_lock);
       return ret;
}

Upstream patch seems to be missing in RHEL 4

[NETFILTER]: Fix /proc/net/ip_conntrack seq_file operations

http://www.mail-archive.com/bk-commits-head@vger.kernel.org/msg03409.html
Comment 3 Danny Feng 2009-09-28 09:54:01 UTC 
Created attachment 362875 [details]
posted patch
Comment 4 RHEL Program Management 2010-10-12 17:52:00 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 5 Vivek Goyal 2010-10-14 14:40:58 UTC 
Committed in 89.43.EL . RPMS are available at http://people.redhat.com/vgoyal/rhel4/
Comment 16 errata-xmlrpc 2011-02-16 15:57:52 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-2011-0263.html