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| author | Gordon Tetlow <gordon@FreeBSD.org> | 2020-05-12 16:51:11 +0000 |
|---|---|---|
| committer | Gordon Tetlow <gordon@FreeBSD.org> | 2020-05-12 16:51:11 +0000 |
| commit | 8f442d6baad809e315e3ec4506c64920066d7fb9 (patch) | |
| tree | fbc3cf3675310dc1519cb6501bfb7480dcc05ec3 | |
| parent | 97797099e241b0d8132d9609751cecf5421fc890 (diff) | |
| download | src-test2-8f442d6baad809e315e3ec4506c64920066d7fb9.tar.gz src-test2-8f442d6baad809e315e3ec4506c64920066d7fb9.zip | |
Fix insufficient packet length validation in libalias.
Approved by: so
Approved by: re (implicit)
Security: FreeBSD-SA-20:12.libalias
Security: CVE-2020-7454
Notes
Notes:
svn path=/releng/12.1/; revision=360972
| -rw-r--r-- | sys/netinet/libalias/alias.c | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/sys/netinet/libalias/alias.c b/sys/netinet/libalias/alias.c index d5dd8f2d08c9..72c4acfd2f8d 100644 --- a/sys/netinet/libalias/alias.c +++ b/sys/netinet/libalias/alias.c @@ -441,10 +441,15 @@ 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); @@ -463,6 +468,9 @@ 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: @@ -731,10 +739,17 @@ 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, @@ -823,12 +838,19 @@ UdpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize, int create) 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); @@ -921,8 +943,13 @@ 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, @@ -1041,7 +1068,7 @@ 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; @@ -1050,6 +1077,10 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize, int create) 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) |