SNMP: Clear community aliases to avoid dangling pointer (#2215)

Currently not a issue, but reduces UAF hazard in the future

diff --git a/src/snmp_core.cc b/src/snmp_core.cc
index ffd93c2063614d7eb68c4fee49a757e73b170972..c28a412241bbe5a546aa39d5a7c13e8a6120399b 100644 (file)
--- a/src/snmp_core.cc
+++ b/src/snmp_core.cc
@@ -423,7 +423,9 @@ snmpDecodePacket(SnmpRequest * rq)
             snmp_free_pdu(PDU);
         }
         xfree(Community);
             snmp_free_pdu(PDU);
         }
         xfree(Community);

-
+        rq->community = nullptr;
+        rq->session.community = nullptr;
+        rq->session.community_len = 0;

     } else {
         debugs(49, DBG_IMPORTANT, "WARNING: Failed SNMP agent query from : " << rq->from);
         snmp_free_pdu(PDU);
     } else {
         debugs(49, DBG_IMPORTANT, "WARNING: Failed SNMP agent query from : " << rq->from);
         snmp_free_pdu(PDU);