Date: Fri, 13 Jan 2017 08:55:41 +0000 (UTC) From: Ngie Cooper <ngie@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r312048 - stable/11/contrib/bsnmp/lib Message-ID: <201701130855.v0D8tfYI059413@repo.freebsd.org>
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Author: ngie Date: Fri Jan 13 08:55:41 2017 New Revision: 312048 URL: https://svnweb.freebsd.org/changeset/base/312048 Log: MFC r310729: Prevent improper memory accesses after calling snmp_pdu_free and snmp_value_free snmp_pdu_free: set pdu->nbindings to 0 to limit the damage that could happen if a pdu was reused after calling the function, and as both stack and heap allocation types are used in contrib/bsnmp and usr.sbin/bsnmpd. snmp_value_free: NULL out value->v.octetstring.octets after calling free on it to prevent a double-free from occurring. Modified: stable/11/contrib/bsnmp/lib/snmp.c Directory Properties: stable/11/ (props changed) Modified: stable/11/contrib/bsnmp/lib/snmp.c ============================================================================== --- stable/11/contrib/bsnmp/lib/snmp.c Fri Jan 13 08:55:37 2017 (r312047) +++ stable/11/contrib/bsnmp/lib/snmp.c Fri Jan 13 08:55:41 2017 (r312048) @@ -1154,8 +1154,11 @@ snmp_pdu_dump(const struct snmp_pdu *pdu void snmp_value_free(struct snmp_value *value) { - if (value->syntax == SNMP_SYNTAX_OCTETSTRING) + + if (value->syntax == SNMP_SYNTAX_OCTETSTRING) { free(value->v.octetstring.octets); + value->v.octetstring.octets = NULL; + } value->syntax = SNMP_SYNTAX_NULL; } @@ -1216,6 +1219,7 @@ snmp_pdu_free(struct snmp_pdu *pdu) for (i = 0; i < pdu->nbindings; i++) snmp_value_free(&pdu->bindings[i]); + pdu->nbindings = 0; } /*
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