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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 | 1d5d673d173626918584254b7233df088280747f (patch) | |
| tree | 6f793ed56d3cc64a83886bfbdce417240e36c363 | |
| parent | 152f31caec4fa221439dd6a5c018fbf0d0fa4de6 (diff) | |
| download | src-test2-1d5d673d173626918584254b7233df088280747f.tar.gz src-test2-1d5d673d173626918584254b7233df088280747f.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/11.3/; 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 34a1e2abb098..0c92e1ff64ff 100644 --- a/sys/netinet/libalias/alias.c +++ b/sys/netinet/libalias/alias.c @@ -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 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); @@ -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 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) |