Cherry pick: Improve input validation when processing AUTH chunks.
Thanks to Natalie Silvanovich from Google for finding and reporting the
issue found by her in the SCTP userland stack.
diff --git a/usrsctplib/netinet/sctp_input.c b/usrsctplib/netinet/sctp_input.c
index dc2f89e..b7e4aea 100755
--- a/usrsctplib/netinet/sctp_input.c
+++ b/usrsctplib/netinet/sctp_input.c
@@ -2184,7 +2184,7 @@
int init_offset, initack_offset, initack_limit;
int retval;
int error = 0;
- uint8_t auth_chunk_buf[SCTP_PARAM_BUFFER_SIZE];
+ uint8_t auth_chunk_buf[SCTP_CHUNK_BUFFER_SIZE];
#if defined(__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
struct socket *so;
@@ -2379,7 +2379,7 @@
if (auth_skipped) {
struct sctp_auth_chunk *auth;
- if (auth_len <= SCTP_PARAM_BUFFER_SIZE) {
+ if (auth_len <= SCTP_CHUNK_BUFFER_SIZE) {
auth = (struct sctp_auth_chunk *)sctp_m_getptr(m, auth_offset, auth_len, auth_chunk_buf);
} else {
auth = NULL;
@@ -4851,11 +4851,13 @@
if (auth_skipped && (stcb != NULL)) {
struct sctp_auth_chunk *auth;
- auth = (struct sctp_auth_chunk *)
- sctp_m_getptr(m, auth_offset,
- auth_len, chunk_buf);
- got_auth = 1;
- auth_skipped = 0;
+ if (auth_len <= SCTP_CHUNK_BUFFER_SIZE) {
+ auth = (struct sctp_auth_chunk *)sctp_m_getptr(m, auth_offset, auth_len, chunk_buf);
+ got_auth = 1;
+ auth_skipped = 0;
+ } else {
+ auth = NULL;
+ }
if ((auth == NULL) || sctp_handle_auth(stcb, auth, m,
auth_offset)) {
/* auth HMAC failed so dump it */