RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Description of problem:

NB. This is not limited to RHEL6 (also affects RHEL5/7).

Due to the way snmpd handles file descriptors when forking scripts for 'pass' or 'extend', on systems with very large numbers of FD, this will consume CPU and take several seconds for each OID.

Please consider back porting the following fix:
https://sourceforge.net/p/net-snmp/code/ci/0e4bf5d3659c459128c0f98926b0db7296e9c49f/


Version-Release number of selected component (if applicable):
Observed on all releases, including 5.7


How reproducible:
Every time

Steps to Reproduce:
1. increase fs-max/nofile to large value (32626630 in test case)
2. configure snmp pass or extend in snmpd.conf
3. get/walk the OID

Actual results:
Several seconds of 100% CPU utilisation, SNMP response takes several seconds.
snmpwalk (for 'pass' that support this) time out.

Expected results:
Immediate response, minimal CPU utilisation


Additional info:
Please consider back porting the following fix:
https://sourceforge.net/p/net-snmp/code/ci/0e4bf5d3659c459128c0f98926b0db7296e9c49f/

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.

https://rhn.redhat.com/errata/RHSA-2015-1385.html