Date: Tue, 12 May 2020 16:49:05 +0000 (UTC) From: Ed Maste <emaste@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: r360971 - in stable: 11/sys/netinet/libalias 12/sys/netinet/libalias Message-ID: <202005121649.04CGn5Pp057906@repo.freebsd.org>
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Author: emaste Date: Tue May 12 16:49:04 2020 New Revision: 360971 URL: https://svnweb.freebsd.org/changeset/base/360971 Log: MFC r360967: libalias: validate packet lengths before accessing headers admbugs: 956 Submitted by: ae Reported by: Lucas Leong (@_wmliang_) of Trend Micro Zero Day Initiative Reported by: Vishnu working with Trend Micro Zero Day Initiative Approved by: so Security: FreeBSD-SA-20:12.libalias Security: CVE-2020-7454 Security: ZDI-CAN-10624, ZDI-CAN-10850 Modified: stable/11/sys/netinet/libalias/alias.c Directory Properties: stable/11/ (props changed) Changes in other areas also in this revision: Modified: stable/12/sys/netinet/libalias/alias.c Directory Properties: stable/12/ (props changed) Modified: stable/11/sys/netinet/libalias/alias.c ============================================================================== --- stable/11/sys/netinet/libalias/alias.c Tue May 12 16:46:14 2020 (r360970) +++ stable/11/sys/netinet/libalias/alias.c Tue May 12 16:49:04 2020 (r360971) @@ -439,10 +439,15 @@ fragment contained in ICMP data section */ static int IcmpAliasIn(struct libalias *la, struct ip *pip) { - int iresult; struct icmp *ic; + int dlen, iresult; LIBALIAS_LOCK_ASSERT(la); + + dlen = ntohs(pip->ip_len) - (pip->ip_hl << 2); + if (dlen < ICMP_MINLEN) + return (PKT_ALIAS_IGNORED); + /* Return if proxy-only mode is enabled */ if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY) return (PKT_ALIAS_OK); @@ -461,6 +466,9 @@ IcmpAliasIn(struct libalias *la, struct ip *pip) case ICMP_SOURCEQUENCH: case ICMP_TIMXCEED: case ICMP_PARAMPROB: + if (dlen < ICMP_ADVLENMIN || + dlen < ICMP_ADVLEN(ic)) + return (PKT_ALIAS_IGNORED); iresult = IcmpAliasIn2(la, pip); break; case ICMP_ECHO: @@ -729,10 +737,17 @@ UdpAliasIn(struct libalias *la, struct ip *pip) { struct udphdr *ud; struct alias_link *lnk; + int dlen; LIBALIAS_LOCK_ASSERT(la); + dlen = ntohs(pip->ip_len) - (pip->ip_hl << 2); + if (dlen < sizeof(struct udphdr)) + return (PKT_ALIAS_IGNORED); + ud = (struct udphdr *)ip_next(pip); + if (dlen < ntohs(ud->uh_ulen)) + return (PKT_ALIAS_IGNORED); lnk = FindUdpTcpIn(la, pip->ip_src, pip->ip_dst, ud->uh_sport, ud->uh_dport, @@ -821,12 +836,19 @@ UdpAliasOut(struct libalias *la, struct ip *pip, int m u_short dest_port; u_short proxy_server_port; int proxy_type; - int error; + int dlen, error; LIBALIAS_LOCK_ASSERT(la); /* Return if proxy-only mode is enabled and not proxyrule found.*/ + dlen = ntohs(pip->ip_len) - (pip->ip_hl << 2); + if (dlen < sizeof(struct udphdr)) + return (PKT_ALIAS_IGNORED); + ud = (struct udphdr *)ip_next(pip); + if (dlen < ntohs(ud->uh_ulen)) + return (PKT_ALIAS_IGNORED); + proxy_type = ProxyCheck(la, &proxy_server_address, &proxy_server_port, pip->ip_src, pip->ip_dst, ud->uh_dport, pip->ip_p); @@ -919,8 +941,13 @@ TcpAliasIn(struct libalias *la, struct ip *pip) { struct tcphdr *tc; struct alias_link *lnk; + int dlen; LIBALIAS_LOCK_ASSERT(la); + + dlen = ntohs(pip->ip_len) - (pip->ip_hl << 2); + if (dlen < sizeof(struct tcphdr)) + return (PKT_ALIAS_IGNORED); tc = (struct tcphdr *)ip_next(pip); lnk = FindUdpTcpIn(la, pip->ip_src, pip->ip_dst, @@ -1039,7 +1066,7 @@ TcpAliasIn(struct libalias *la, struct ip *pip) static int TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize, int create) { - int proxy_type, error; + int dlen, proxy_type, error; u_short dest_port; u_short proxy_server_port; struct in_addr dest_address; @@ -1048,6 +1075,10 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int m struct alias_link *lnk; LIBALIAS_LOCK_ASSERT(la); + + dlen = ntohs(pip->ip_len) - (pip->ip_hl << 2); + if (dlen < sizeof(struct tcphdr)) + return (PKT_ALIAS_IGNORED); tc = (struct tcphdr *)ip_next(pip); if (create)
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