svn commit: r351654 - head/sys/netinet
Michael Tuexen
tuexen at FreeBSD.org
Sun Sep 1 10:09:54 UTC 2019
Author: tuexen
Date: Sun Sep 1 10:09:53 2019
New Revision: 351654
URL: https://svnweb.freebsd.org/changeset/base/351654
Log:
Improve the handling of state cookie parameters in INIT-ACK chunks.
This fixes problem with parameters indicating a zero length or partial
parameters after an unknown parameter indicating to stop processing. It
also fixes a problem with state cookie parameters after unknown
parametes indicating to stop porcessing.
Thanks to Mark Wodrich from Google for finding two of these issues
by fuzz testing the userland stack and reporting them in
https://github.com/sctplab/usrsctp/issues/355
and
https://github.com/sctplab/usrsctp/issues/352
MFC after: 3 days
Modified:
head/sys/netinet/sctp_input.c
head/sys/netinet/sctp_output.c
head/sys/netinet/sctp_output.h
Modified: head/sys/netinet/sctp_input.c
==============================================================================
--- head/sys/netinet/sctp_input.c Sun Sep 1 06:40:58 2019 (r351653)
+++ head/sys/netinet/sctp_input.c Sun Sep 1 10:09:53 2019 (r351654)
@@ -444,22 +444,48 @@ sctp_process_init_ack(struct mbuf *m, int iphlen, int
{
struct sctp_association *asoc;
struct mbuf *op_err;
- int retval, abort_flag;
- uint32_t initack_limit;
+ int retval, abort_flag, cookie_found;
+ int initack_limit;
int nat_friendly = 0;
/* First verify that we have no illegal param's */
abort_flag = 0;
+ cookie_found = 0;
op_err = sctp_arethere_unrecognized_parameters(m,
(offset + sizeof(struct sctp_init_chunk)),
- &abort_flag, (struct sctp_chunkhdr *)cp, &nat_friendly);
+ &abort_flag, (struct sctp_chunkhdr *)cp,
+ &nat_friendly, &cookie_found);
if (abort_flag) {
/* Send an abort and notify peer */
sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, SCTP_SO_NOT_LOCKED);
*abort_no_unlock = 1;
return (-1);
}
+ if (!cookie_found) {
+ uint16_t len;
+
+ len = (uint16_t)(sizeof(struct sctp_error_missing_param) + sizeof(uint16_t));
+ /* We abort with an error of missing mandatory param */
+ op_err = sctp_get_mbuf_for_msg(len, 0, M_NOWAIT, 1, MT_DATA);
+ if (op_err != NULL) {
+ struct sctp_error_missing_param *cause;
+
+ SCTP_BUF_LEN(op_err) = len;
+ cause = mtod(op_err, struct sctp_error_missing_param *);
+ /* Subtract the reserved param */
+ cause->cause.code = htons(SCTP_CAUSE_MISSING_PARAM);
+ cause->cause.length = htons(len);
+ cause->num_missing_params = htonl(1);
+ cause->type[0] = htons(SCTP_STATE_COOKIE);
+ }
+ sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
+ src, dst, sh, op_err,
+ mflowtype, mflowid,
+ vrf_id, net->port);
+ *abort_no_unlock = 1;
+ return (-3);
+ }
asoc = &stcb->asoc;
asoc->peer_supports_nat = (uint8_t)nat_friendly;
/* process the peer's parameters in the INIT-ACK */
@@ -524,40 +550,8 @@ sctp_process_init_ack(struct mbuf *m, int iphlen, int
/* calculate the RTO */
net->RTO = sctp_calculate_rto(stcb, asoc, net, &asoc->time_entered,
SCTP_RTT_FROM_NON_DATA);
- retval = sctp_send_cookie_echo(m, offset, stcb, net);
- if (retval < 0) {
- /*
- * No cookie, we probably should send a op error. But in any
- * case if there is no cookie in the INIT-ACK, we can
- * abandon the peer, its broke.
- */
- if (retval == -3) {
- uint16_t len;
-
- len = (uint16_t)(sizeof(struct sctp_error_missing_param) + sizeof(uint16_t));
- /* We abort with an error of missing mandatory param */
- op_err = sctp_get_mbuf_for_msg(len, 0, M_NOWAIT, 1, MT_DATA);
- if (op_err != NULL) {
- struct sctp_error_missing_param *cause;
-
- SCTP_BUF_LEN(op_err) = len;
- cause = mtod(op_err, struct sctp_error_missing_param *);
- /* Subtract the reserved param */
- cause->cause.code = htons(SCTP_CAUSE_MISSING_PARAM);
- cause->cause.length = htons(len);
- cause->num_missing_params = htonl(1);
- cause->type[0] = htons(SCTP_STATE_COOKIE);
- }
- sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
- src, dst, sh, op_err,
- mflowtype, mflowid,
- vrf_id, net->port);
- *abort_no_unlock = 1;
- }
- return (retval);
- }
-
- return (0);
+ retval = sctp_send_cookie_echo(m, offset, initack_limit, stcb, net);
+ return (retval);
}
static void
Modified: head/sys/netinet/sctp_output.c
==============================================================================
--- head/sys/netinet/sctp_output.c Sun Sep 1 06:40:58 2019 (r351653)
+++ head/sys/netinet/sctp_output.c Sun Sep 1 10:09:53 2019 (r351654)
@@ -4970,7 +4970,10 @@ sctp_send_initiate(struct sctp_inpcb *inp, struct sctp
struct mbuf *
sctp_arethere_unrecognized_parameters(struct mbuf *in_initpkt,
- int param_offset, int *abort_processing, struct sctp_chunkhdr *cp, int *nat_friendly)
+ int param_offset, int *abort_processing,
+ struct sctp_chunkhdr *cp,
+ int *nat_friendly,
+ int *cookie_found)
{
/*
* Given a mbuf containing an INIT or INIT-ACK with the param_offset
@@ -4993,6 +4996,9 @@ sctp_arethere_unrecognized_parameters(struct mbuf *in_
uint16_t ptype, plen, padded_size;
*abort_processing = 0;
+ if (cookie_found != NULL) {
+ *cookie_found = 0;
+ }
mat = in_initpkt;
limit = ntohs(cp->chunk_length) - sizeof(struct sctp_init_chunk);
at = param_offset;
@@ -5021,12 +5027,17 @@ sctp_arethere_unrecognized_parameters(struct mbuf *in_
switch (ptype) {
/* Param's with variable size */
case SCTP_HEARTBEAT_INFO:
- case SCTP_STATE_COOKIE:
case SCTP_UNRECOG_PARAM:
case SCTP_ERROR_CAUSE_IND:
/* ok skip fwd */
at += padded_size;
break;
+ case SCTP_STATE_COOKIE:
+ if (cookie_found != NULL) {
+ *cookie_found = 1;
+ }
+ at += padded_size;
+ break;
/* Param's with variable size within a range */
case SCTP_CHUNK_LIST:
case SCTP_SUPPORTED_CHUNK_EXT:
@@ -5568,7 +5579,9 @@ sctp_send_initiate_ack(struct sctp_inpcb *inp, struct
abort_flag = 0;
op_err = sctp_arethere_unrecognized_parameters(init_pkt,
(offset + sizeof(struct sctp_init_chunk)),
- &abort_flag, (struct sctp_chunkhdr *)init_chk, &nat_friendly);
+ &abort_flag,
+ (struct sctp_chunkhdr *)init_chk,
+ &nat_friendly, NULL);
if (abort_flag) {
do_a_abort:
if (op_err == NULL) {
@@ -9001,7 +9014,7 @@ sctp_queue_op_err(struct sctp_tcb *stcb, struct mbuf *
int
sctp_send_cookie_echo(struct mbuf *m,
- int offset,
+ int offset, int limit,
struct sctp_tcb *stcb,
struct sctp_nets *net)
{
@@ -9027,18 +9040,30 @@ sctp_send_cookie_echo(struct mbuf *m,
}
ptype = ntohs(phdr->param_type);
plen = ntohs(phdr->param_length);
+ if (plen < sizeof(struct sctp_paramhdr)) {
+ return (-6);
+ }
if (ptype == SCTP_STATE_COOKIE) {
int pad;
/* found the cookie */
- if ((pad = (plen % 4))) {
- plen += 4 - pad;
+ if (at + plen > limit) {
+ return (-7);
}
cookie = SCTP_M_COPYM(m, at, plen, M_NOWAIT);
if (cookie == NULL) {
/* No memory */
return (-2);
}
+ if ((pad = (plen % 4)) > 0) {
+ pad = 4 - pad;
+ }
+ if (pad > 0) {
+ cookie = sctp_pad_lastmbuf(cookie, pad, NULL);
+ if (cookie == NULL) {
+ return (-8);
+ }
+ }
#ifdef SCTP_MBUF_LOGGING
if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
sctp_log_mbc(cookie, SCTP_MBUF_ICOPY);
@@ -9064,7 +9089,7 @@ sctp_send_cookie_echo(struct mbuf *m,
chk->rec.chunk_id.id = SCTP_COOKIE_ECHO;
chk->rec.chunk_id.can_take_data = 0;
chk->flags = CHUNK_FLAGS_FRAGMENT_OK;
- chk->send_size = plen;
+ chk->send_size = SCTP_SIZE32(plen);
chk->sent = SCTP_DATAGRAM_UNSENT;
chk->snd_count = 0;
chk->asoc = &stcb->asoc;
Modified: head/sys/netinet/sctp_output.h
==============================================================================
--- head/sys/netinet/sctp_output.h Sun Sep 1 06:40:58 2019 (r351653)
+++ head/sys/netinet/sctp_output.h Sun Sep 1 10:09:53 2019 (r351654)
@@ -92,11 +92,11 @@ sctp_send_initiate_ack(struct sctp_inpcb *, struct sct
struct mbuf *
sctp_arethere_unrecognized_parameters(struct mbuf *, int, int *,
- struct sctp_chunkhdr *, int *);
+ struct sctp_chunkhdr *, int *, int *);
void sctp_queue_op_err(struct sctp_tcb *, struct mbuf *);
int
-sctp_send_cookie_echo(struct mbuf *, int, struct sctp_tcb *,
+sctp_send_cookie_echo(struct mbuf *, int, int, struct sctp_tcb *,
struct sctp_nets *);
void sctp_send_cookie_ack(struct sctp_tcb *);
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