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
This commit is contained in:
Xin LI 2015-01-27 19:35:38 +00:00
parent 38f2a43815
commit 6a58f0e913

View File

@ -3649,6 +3649,9 @@ sctp_handle_stream_reset_response(struct sctp_tcb *stcb,
/* 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 @@ __attribute__((noinline))
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)
break;
param_len = ntohs(ph->param_length);
if (param_len < (int)sizeof(struct sctp_stream_reset_tsn_request)) {
/* bad param */
if (ph == NULL) {
/* TSNH */
break;
}
ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset, min(param_len, (int)sizeof(cstore)),
param_len = ntohs(ph->param_length);
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, 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 @@ __attribute__((noinline))
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 @@ __attribute__((noinline))
} 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 @@ __attribute__((noinline))
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 @@ __attribute__((noinline))
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 */