diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/sctp/sm_make_chunk.c | 46 | ||||
| -rw-r--r-- | net/sctp/sm_statefuns.c | 50 |
2 files changed, 96 insertions, 0 deletions
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. * |