svn commit: r353060 - head/sys/netinet

[Michael Tuexen]

Author: tuexen
Date: Thu Oct  3 18:36:54 2019
New Revision: 353060
URL: https://svnweb.freebsd.org/changeset/base/353060

Log:
  Add missing input validation. This could result in reading from
  uninitialized memory.
  The issue was found by OSS-Fuzz for usrsctp  and reported in
  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=17780
  
  MFC after:		3 days

Modified:
  head/sys/netinet/sctp_asconf.c

Modified: head/sys/netinet/sctp_asconf.c
==============================================================================
--- head/sys/netinet/sctp_asconf.c	Thu Oct  3 18:24:41 2019	(r353059)
+++ head/sys/netinet/sctp_asconf.c	Thu Oct  3 18:36:54 2019	(r353060)
@@ -169,10 +169,16 @@ sctp_process_asconf_add_ip(struct sockaddr *src, struc
 #endif
 
 	aparam_length = ntohs(aph->ph.param_length);
+	if (aparam_length < sizeof(struct sctp_asconf_paramhdr) + sizeof(struct sctp_paramhdr)) {
+		return (NULL);
+	}
 	ph = (struct sctp_paramhdr *)(aph + 1);
 	param_type = ntohs(ph->param_type);
 #if defined(INET) || defined(INET6)
 	param_length = ntohs(ph->param_length);
+	if (param_length + sizeof(struct sctp_asconf_paramhdr) != aparam_length) {
+		return (NULL);
+	}
 #endif
 	sa = &store.sa;
 	switch (param_type) {
@@ -325,8 +331,14 @@ sctp_process_asconf_delete_ip(struct sockaddr *src,
 	aparam_length = ntohs(aph->ph.param_length);
 	ph = (struct sctp_paramhdr *)(aph + 1);
 	param_type = ntohs(ph->param_type);
+	if (aparam_length < sizeof(struct sctp_asconf_paramhdr) + sizeof(struct sctp_paramhdr)) {
+		return (NULL);
+	}
 #if defined(INET) || defined(INET6)
 	param_length = ntohs(ph->param_length);
+	if (param_length + sizeof(struct sctp_asconf_paramhdr) != aparam_length) {
+		return (NULL);
+	}
 #endif
 	sa = &store.sa;
 	switch (param_type) {
@@ -454,10 +466,16 @@ sctp_process_asconf_set_primary(struct sockaddr *src,
 #endif
 
 	aparam_length = ntohs(aph->ph.param_length);
+	if (aparam_length < sizeof(struct sctp_asconf_paramhdr) + sizeof(struct sctp_paramhdr)) {
+		return (NULL);
+	}
 	ph = (struct sctp_paramhdr *)(aph + 1);
 	param_type = ntohs(ph->param_type);
 #if defined(INET) || defined(INET6)
 	param_length = ntohs(ph->param_length);
+	if (param_length + sizeof(struct sctp_asconf_paramhdr) != aparam_length) {
+		return (NULL);
+	}
 #endif
 	sa = &store.sa;
 	switch (param_type) {