Author: delphij
Date: Tue Jan 27 19:35:38 2015
New Revision: 277805
URL: https://svnweb.freebsd.org/changeset/base/277805
Log:
Fix SCTP stream reset vulnerability.
We would like to acknowledge Gerasimos Dimitriadis who reported
the issue and Michael Tuexen who analyzed and provided the
fix.
Security: FreeBSD-SA-15:03.sctp
Security: CVE-2014-8613
Submitted by: tuexen
Modified:
head/sys/netinet/sctp_input.c
Modified: head/sys/netinet/sctp_input.c
==============================================================================
--- head/sys/netinet/sctp_input.c Tue Jan 27 19:35:36 2015
(r277804)
+++ head/sys/netinet/sctp_input.c Tue Jan 27 19:35:38 2015
(r277805)
@@ -3649,6 +3649,9 @@ sctp_handle_stream_reset_response(struct
/* huh ? */
return (0);
}
+ if (ntohs(respin->ph.param_length) <
sizeof(struct sctp_stream_reset_response_tsn)) {
+ return (0);
+ }
if (action ==
SCTP_STREAM_RESET_RESULT_PERFORMED) {
resp = (struct
sctp_stream_reset_response_tsn *)respin;
asoc->stream_reset_outstanding--;
@@ -4037,7 +4040,7 @@ __attribute__((noinline))
sctp_handle_stream_reset(struct sctp_tcb *stcb, struct mbuf *m, int
offset,
struct sctp_chunkhdr *ch_req)
{
- int chk_length, param_len, ptype;
+ uint16_t remaining_length, param_len, ptype;
struct sctp_paramhdr pstore;
uint8_t cstore[SCTP_CHUNK_BUFFER_SIZE];
uint32_t seq = 0;
@@ -4050,7 +4053,7 @@ __attribute__((noinline))
int num_param = 0;
/* now it may be a reset or a reset-response */
- chk_length = ntohs(ch_req->chunk_length);
+ remaining_length = ntohs(ch_req->chunk_length) - sizeof(struct
sctp_chunkhdr);
/* setup for adding the response */
sctp_alloc_a_chunk(stcb, chk);
@@ -4088,20 +4091,27 @@ strres_nochunk:
ch->chunk_length = htons(chk->send_size);
SCTP_BUF_LEN(chk->data) = SCTP_SIZE32(chk->send_size);
offset += sizeof(struct sctp_chunkhdr);
- while ((size_t)chk_length >= sizeof(struct
sctp_stream_reset_tsn_request)) {
+ while (remaining_length >= sizeof(struct sctp_paramhdr)) {
ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
sizeof(pstore), (uint8_t *) & pstore);
- if (ph == NULL)
+ if (ph == NULL) {
+ /* TSNH */
break;
+ }
param_len = ntohs(ph->param_length);
- if (param_len < (int)sizeof(struct
sctp_stream_reset_tsn_request)) {
- /* bad param */
+ if ((param_len > remaining_length) ||
+ (param_len < (sizeof(struct sctp_paramhdr) +
sizeof(uint32_t)))) {
+ /* bad parameter length */
break;
}
- ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
min(param_len, (int)sizeof(cstore)),
+ ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
min(param_len, sizeof(cstore)),
(uint8_t *) & cstore);
+ if (ph == NULL) {
+ /* TSNH */
+ break;
+ }
ptype = ntohs(ph->param_type);
num_param++;
- if (param_len > (int)sizeof(cstore)) {
+ if (param_len > sizeof(cstore)) {
trunc = 1;
} else {
trunc = 0;
@@ -4113,6 +4123,9 @@ strres_nochunk:
if (ptype == SCTP_STR_RESET_OUT_REQUEST) {
struct sctp_stream_reset_out_request *req_out;
+ if (param_len < sizeof(struct
sctp_stream_reset_out_request)) {
+ break;
+ }
req_out = (struct sctp_stream_reset_out_request *)ph;
num_req++;
if (stcb->asoc.stream_reset_outstanding) {
@@ -4126,12 +4139,18 @@ strres_nochunk:
} else if (ptype == SCTP_STR_RESET_ADD_OUT_STREAMS) {
struct sctp_stream_reset_add_strm *str_add;
+ if (param_len < sizeof(struct
sctp_stream_reset_add_strm)) {
+ break;
+ }
str_add = (struct sctp_stream_reset_add_strm *)ph;
num_req++;
sctp_handle_str_reset_add_strm(stcb, chk, str_add);
} else if (ptype == SCTP_STR_RESET_ADD_IN_STREAMS) {
struct sctp_stream_reset_add_strm *str_add;
+ if (param_len < sizeof(struct
sctp_stream_reset_add_strm)) {
+ break;
+ }
str_add = (struct sctp_stream_reset_add_strm *)ph;
num_req++;
sctp_handle_str_reset_add_out_strm(stcb, chk, str_add);
@@ -4156,6 +4175,9 @@ strres_nochunk:
struct sctp_stream_reset_response *resp;
uint32_t result;
+ if (param_len < sizeof(struct
sctp_stream_reset_response)) {
+ break;
+ }
resp = (struct sctp_stream_reset_response *)ph;
seq = ntohl(resp->response_seq);
result = ntohl(resp->result);
@@ -4167,7 +4189,11 @@ strres_nochunk:
break;
}
offset += SCTP_SIZE32(param_len);
- chk_length -= SCTP_SIZE32(param_len);
+ if (remaining_length >= SCTP_SIZE32(param_len)) {
+ remaining_length -= SCTP_SIZE32(param_len);
+ } else {
+ remaining_length = 0;
+ }
}
if (num_req == 0) {
/* we have no response free the stuff */
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