[Pkg-net-snmp-devel] Bug#593197: snmpd segfaults randomly on amd64 xen domU

[Matti Saarinen]

Package: snmpd
Version: 5.4.1~dfsg-12
Severity: important


We have seen some random crashes of snmpd. The crashes happen on xen domU hosts.
I managed to reproduce the crash by querying snmpd constantly. Normally the crashes
happen approximately once a month. 

The only log message left behind after the crash is the following one.

kernel: [3145305.998225] snmpd[2097]: segfault at 0 ip 7f1db543d72e sp 7fffffffcce0 error 6 in libnetsnmpmibs.so.15.1.0[7f1db5382000+118000]

While trying the reproduce the crash in a controlled manner I run the snmpd under
gdb. Below is the stack strace. Unfortunately, I am not a programmer nor do I know
how to gdb in the most effective way so there may be some relevant information missing.

(gdb) bt
#0  0x00007f2944fdb5b4 in var_hrswrun () from /usr/lib/libnetsnmpmibs.so.15
#1  0x00007f29453013fd in netsnmp_old_api_helper () from /usr/lib/libnetsnmphelpers.so.15
#2  0x00007f2945536097 in netsnmp_call_handlers () from /usr/lib/libnetsnmpagent.so.15
#3  0x00007f29455271d1 in handle_var_requests () from /usr/lib/libnetsnmpagent.so.15
#4  0x00007f2945528d5b in handle_pdu () from /usr/lib/libnetsnmpagent.so.15
#5  0x00007f294552b2c8 in netsnmp_handle_request () from /usr/lib/libnetsnmpagent.so.15
#6  0x00007f294552be12 in handle_snmp_packet () from /usr/lib/libnetsnmpagent.so.15
#7  0x00007f2944d11ba9 in ?? () from /usr/lib/libnetsnmp.so.15
#8  0x00007f2944d13d8d in _sess_read () from /usr/lib/libnetsnmp.so.15
#9  0x00007f2944d14339 in snmp_sess_read () from /usr/lib/libnetsnmp.so.15
#10 0x00007f2944d1438b in snmp_read () from /usr/lib/libnetsnmp.so.15
#11 0x0000000000404cab in main ()

I can try to provide more information if needed.

Regards,

Matti Saarinen

-- System Information:
Debian Release: 5.0.5
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.26-2-xen-amd64 (SMP w/1 CPU core)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/bash

Versions of packages snmpd depends on:
ii  adduser                    3.110         add and remove users and groups
ii  debconf                    1.5.24        Debian configuration management sy
ii  libc6                      2.7-18lenny4  GNU C Library: Shared libraries
ii  libsnmp15                  5.4.1~dfsg-12 SNMP (Simple Network Management Pr
ii  libwrap0                   7.6.q-16      Wietse Venema's TCP wrappers libra

snmpd recommends no packages.

snmpd suggests no packages.

-- debconf information:
  snmpd/upgradefrom521: