From: Alex Rousskov <rousskov@measurement-factory.com>
Date: Mon, 8 Sep 2025 06:40:02 +0000 (+0000)
Subject: Do not assert when debugging SNMP requests with long OIDs (#2150)
X-Git-Tag: SQUID_7_2~31
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ba3e552ff459e5570c33c727a01c6bfa929d581e;p=thirdparty%2Fsquid.git

Do not assert when debugging SNMP requests with long OIDs (#2150)

    FATAL: assertion failed: MemBuf.cc: "new_cap > (size_t) capacity"

Also fixes repeated same-buffer snmpDebugOid() calls that used to
accumulate stale content in snmpTreeNext():

    snmpTreeNext: Current : .1.3.6.1.4.1.3495
    snmpTreeNext: Next : .1.3.6.1.4.1.3495.1.3.6.1.4.1.3495.1.1.1.0

Current snmpDebugOid() callers have been checked for compatibility with
this fix. Fixing snmpDebugOid() API is out of this surgical fix scope.
---

diff --git a/src/snmp_core.cc b/src/snmp_core.cc
index cc41fc727d..f220dd45f2 100644
--- a/src/snmp_core.cc
+++ b/src/snmp_core.cc
@@ -1057,8 +1057,7 @@ snmpDebugOid(oid * Name, snint Len, MemBuf &outbuf)
 {
     char mbuf[16];
     int x;
-    if (outbuf.isNull())
-        outbuf.init(16, MAX_IPSTRLEN);
+    outbuf.reset();
 
     for (x = 0; x < Len; ++x) {
         size_t bytes = snprintf(mbuf, sizeof(mbuf), ".%u", (unsigned int) Name[x]);