Created attachment 476497 [details]
rsyslogd crash

Description of problem:
RHEL 5 rsyslog includes a patch, rsyslog-3.22.1-unlimitedselect.patch, that has no effect on the final build due to the autoconf version in RHEL 5 (it's too old).  As a result, rsyslog can crash with large numbers of clients.

Version-Release number of selected component (if applicable):
rsyslog-3.22.1-3.el5_5.1

How reproducible:
every time

Steps to Reproduce:
0. Set SELinux in Permissive mode or Disabled
     setenforce Permissive
   The policies prevent rsyslogd from increasing the limit on open files;
   this is a separate problem with the policies and I'll open another bz
   for it.
1. Update rsyslog configuration and start it
     vim /etc/sysconfig/rsyslog
         SYSLOGD_OPTIONS="-c3"
     vim /etc/rsyslog.conf
         # Add these lines after '$ModLoad imuxsock' line
         $ModLoad imtcp.so
         $MaxOpenFiles 2100
         $InputTCPMaxSessions 1100
         $InputTCPServerRun 514
     service rsyslog start
2. Download rsyslog-4.6.5 to get the tcpflood test program
     cd /tmp
     wget http://www.rsyslog.com/files/download/rsyslog/rsyslog-4.6.5.tar.gz
     tar xzf rsyslog-4.6.5.tar.gz
     cd rsyslog-4.6.5
     ./configure
     cd tests
     make tcpflood
3. Run tcpflood against the server
     cd /tmp/rsyslog-4.6.5/tests
     ./tcpflood -p514 -c1100 -m1000
  
Actual results:
rsyslogd crashes

Expected results:
rsyslogd handles the load

Additional info:
Traceback from rsyslogd is attached

You can see that the ulimited select patch is ineffective during the rpmbuild:

[rpmbuild@localhost SPECS]$ rpmbuild -bc rsyslog.spec
Executing(%prep): /bin/sh -e /home/rpmbuild/build/tmp/rpm-tmp.81244
...
+ echo 'Patch #0 (rsyslog-3.22.1-unlimitedselect.patch):'
Patch #0 (rsyslog-3.22.1-unlimitedselect.patch):
...
+ aclocal
configure.ac:4: error: Autoconf version 2.61 or higher is required
configure.ac:4: the top level
autom4te: /usr/bin/m4 failed with exit status: 63
aclocal: autom4te failed with exit status: 63
+ exit 0
...
+ ./configure --build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu --target=x86_64-redhat-linux-gnu --program-prefix= --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/usr/com --mandir=/usr/share/man --infodir=/usr/share/info --sbindir=/sbin --disable-static --enable-mysql --enable-pgsql --enable-gssapi-krb5 --enable-imfile --enable-gnutls --enable-unlimited-select
configure: WARNING: unrecognized options: --enable-unlimited-select
...

[rpmbuild@localhost SPECS]$ cd ../BUILD/rsyslog-3.22.1/
[rpmbuild@localhost rsyslog-3.22.1]$ grep -i unlimited config.h
[rpmbuild@localhost rsyslog-3.22.1]$