summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/net/sctp/sm.h3
-rw-r--r--include/net/sctp/structs.h1
-rw-r--r--net/sctp/sm_make_chunk.c46
-rw-r--r--net/sctp/sm_statefuns.c50
4 files changed, 100 insertions, 0 deletions
diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index cc71f36..e8e3a64 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -246,6 +246,9 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *,
int, __be16);
struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
union sctp_addr *addr);
+int sctp_verify_asconf(const struct sctp_association *asoc,
+ struct sctp_paramhdr *param_hdr, void *chunk_end,
+ struct sctp_paramhdr **errp);
struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
struct sctp_chunk *asconf);
int sctp_process_asconf_ack(struct sctp_association *asoc,
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index c2fe2dc..490a292 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -421,6 +421,7 @@ struct sctp_signed_cookie {
* internally.
*/
union sctp_addr_param {
+ struct sctp_paramhdr p;
struct sctp_ipv4addr_param v4;
struct sctp_ipv6addr_param v6;
};
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 2e34220..23ae37e 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2499,6 +2499,52 @@ static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
return SCTP_ERROR_NO_ERROR;
}
+/* Verify the ASCONF packet before we process it. */
+int sctp_verify_asconf(const struct sctp_association *asoc,
+ struct sctp_paramhdr *param_hdr, void *chunk_end,
+ struct sctp_paramhdr **errp) {
+ sctp_addip_param_t *asconf_param;
+ union sctp_params param;
+ int length, plen;
+
+ param.v = (sctp_paramhdr_t *) param_hdr;
+ while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) {
+ length = ntohs(param.p->length);
+ *errp = param.p;
+
+ if (param.v > chunk_end - length ||
+ length < sizeof(sctp_paramhdr_t))
+ return 0;
+
+ switch (param.p->type) {
+ case SCTP_PARAM_ADD_IP:
+ case SCTP_PARAM_DEL_IP:
+ case SCTP_PARAM_SET_PRIMARY:
+ asconf_param = (sctp_addip_param_t *)param.v;
+ plen = ntohs(asconf_param->param_hdr.length);
+ if (plen < sizeof(sctp_addip_param_t) +
+ sizeof(sctp_paramhdr_t))
+ return 0;
+ break;
+ case SCTP_PARAM_SUCCESS_REPORT:
+ case SCTP_PARAM_ADAPTATION_LAYER_IND:
+ if (length != sizeof(sctp_addip_param_t))
+ return 0;
+
+ break;
+ default:
+ break;
+ }
+
+ param.v += WORD_ROUND(length);
+ }
+
+ if (param.v != chunk_end)
+ return 0;
+
+ return 1;
+}
+
/* Process an incoming ASCONF chunk with the next expected serial no. and
* return an ASCONF_ACK chunk to be sent in response.
*/
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index caed19d..a583d67 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -117,6 +117,13 @@ static sctp_disposition_t sctp_sf_violation_chunklen(
void *arg,
sctp_cmd_seq_t *commands);
+static sctp_disposition_t sctp_sf_violation_paramlen(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+
static sctp_disposition_t sctp_sf_violation_ctsn(
const struct sctp_endpoint *ep,
const struct sctp_association *asoc,
@@ -3296,8 +3303,11 @@ sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
{
struct sctp_chunk *chunk = arg;
struct sctp_chunk *asconf_ack = NULL;
+ struct sctp_paramhdr *err_param = NULL;
sctp_addiphdr_t *hdr;
+ union sctp_addr_param *addr_param;
__u32 serial;
+ int length;
if (!sctp_vtag_verify(chunk, asoc)) {
sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
@@ -3313,6 +3323,20 @@ sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
hdr = (sctp_addiphdr_t *)chunk->skb->data;
serial = ntohl(hdr->serial);
+ addr_param = (union sctp_addr_param *)hdr->params;
+ length = ntohs(addr_param->p.length);
+ if (length < sizeof(sctp_paramhdr_t))
+ return sctp_sf_violation_paramlen(ep, asoc, type,
+ (void *)addr_param, commands);
+
+ /* Verify the ASCONF chunk before processing it. */
+ if (!sctp_verify_asconf(asoc,
+ (sctp_paramhdr_t *)((void *)addr_param + length),
+ (void *)chunk->chunk_end,
+ &err_param))
+ return sctp_sf_violation_paramlen(ep, asoc, type,
+ (void *)&err_param, commands);
+
/* ADDIP 4.2 C1) Compare the value of the serial number to the value
* the endpoint stored in a new association variable
* 'Peer-Serial-Number'.
@@ -3367,6 +3391,7 @@ sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
struct sctp_chunk *asconf_ack = arg;
struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
struct sctp_chunk *abort;
+ struct sctp_paramhdr *err_param = NULL;
sctp_addiphdr_t *addip_hdr;
__u32 sent_serial, rcvd_serial;
@@ -3384,6 +3409,14 @@ sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
rcvd_serial = ntohl(addip_hdr->serial);
+ /* Verify the ASCONF-ACK chunk before processing it. */
+ if (!sctp_verify_asconf(asoc,
+ (sctp_paramhdr_t *)addip_hdr->params,
+ (void *)asconf_ack->chunk_end,
+ &err_param))
+ return sctp_sf_violation_paramlen(ep, asoc, type,
+ (void *)&err_param, commands);
+
if (last_asconf) {
addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
sent_serial = ntohl(addip_hdr->serial);
@@ -3870,6 +3903,23 @@ static sctp_disposition_t sctp_sf_violation_chunklen(
sizeof(err_str));
}
+/*
+ * Handle a protocol violation when the parameter length is invalid.
+ * "Invalid" length is identified as smaller then the minimal length a
+ * given parameter can be.
+ */
+static sctp_disposition_t sctp_sf_violation_paramlen(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands) {
+ char err_str[] = "The following parameter had invalid length:";
+
+ return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
+ sizeof(err_str));
+}
+
/* Handle a protocol violation when the peer trying to advance the
* cumulative tsn ack to a point beyond the max tsn currently sent.
*
OpenPOWER on IntegriCloud