snmpd crash intermittently, when agent/subagent gets restarted with config changes.

Hi Team,


I am getting snmpd crash with below trace, during a system boot, or
snmp restart with config changes.
I am having netsnm version 5.7.2 running in my box.


Trace 1.
==========
Core was generated by `/usr/sbin/snmpd -Lo0-6d -f -x
/var/agentx/master_VRF_1 -p /var/run/openvswitch/'.

Program terminated with signal SIGSEGV, Segmentation fault.

#0  0x00007efc9524cf41 in snmp_sess_read2
(sessp=sessp@entry=0x7efc93cd2040, fdset=fdset@entry=0x7ffd4e23ef00)

    at /usr/src/debug/net-snmp/5.7.2-r1/net-snmp-5.7.2/snmplib/snmp_api.c:6200

6200             if (rc && pss->s_snmp_errno) {

(gdb) bt full

#0  0x00007efc9524cf41 in snmp_sess_read2
(sessp=sessp@entry=0x7efc93cd2040, fdset=fdset@entry=0x7ffd4e23ef00)

    at /usr/src/debug/net-snmp/5.7.2-r1/net-snmp-5.7.2/snmplib/snmp_api.c:6200

        psl = 0x7efc93cd2040

        pss = 0x0

        rc = -1

#1  0x00007efc9524cf8b in snmp_read2 (fdset=0x7ffd4e23ef00) at
/usr/src/debug/net-snmp/5.7.2-r1/net-snmp-5.7.2/snmplib/snmp_api.c:5799

        slp = 0x7efc93cd2040

#2  0x0000000000403ff5 in ?? ()

No symbol table info available.

#3  0x00007efc94e88740 in __libc_start_main (main=0x402600, argc=7,
argv=0x7ffd4e23f1c8, init=<optimized out>, fini=<optimized out>,
rtld_fini=<optimized out>,

    stack_end=0x7ffd4e23f1b8) at
/usr/src/debug/glibc/2.23-r0/git/csu/libc-start.c:289

        self = <optimized out>

        result = <optimized out>

        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {0,
-9062587388492096986, 4210992, 140725914431936, 0, 0,
9061704306574383654, 9205939935531391526},

              mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x4043f0,
0x7ffd4e23f1c8}, data = {prev = 0x0, cleanup = 0x0, canceltype =
4211696}}}

        not_first_call = <optimized out>

#4  0x0000000000404159 in ?? ()

No symbol table info available.



Trace 2:
=======

Core was generated by `/usr/sbin/snmpd -Lo0-6d -f -x
/var/agentx/master_swns -p /var/run/openvswitch/s'.

Program terminated with signal SIGSEGV, Segmentation fault.

#0  _sess_read (sessp=sessp@entry=0xa1,
fdset=fdset@entry=0xffffe9265ea0) at
/usr/src/debug/net-snmp/5.7.2-r1/net-snmp-5.7.2/snmplib/snmp_api.c:5825

5825        netsnmp_transport *transport = slp ? slp->transport : NULL;

(gdb) bt

#0  _sess_read (sessp=sessp@entry=0xa1,
fdset=fdset@entry=0xffffe9265ea0) at
/usr/src/debug/net-snmp/5.7.2-r1/net-snmp-5.7.2/snmplib/snmp_api.c:5825

#1  0x0000ffff9ee3769c in snmp_sess_read2 (sessp=sessp@entry=0xa1,
fdset=fdset@entry=0xffffe9265ea0) at
/usr/src/debug/net-snmp/5.7.2-r1/net-snmp-5.7.2/snmplib/snmp_api.c:6206

#2  0x0000ffff9ee376f4 in snmp_read2 (fdset=0xffffe9265ea0) at
/usr/src/debug/net-snmp/5.7.2-r1/net-snmp-5.7.2/snmplib/snmp_api.c:5808

#3  0x0000000000404584 in ?? ()



This issue is not continously reproducible but seeing intermittently,
when snmp agent/subagent restarts, and snmpwalk happens in the
background.
Please help me understand the issue further and help me with the
patch/ if this issue is already taken care in the upstream.


Thanks,
Surya