sctp: check parameter value of length in ERROR chunk

When an endpoint receives ERROR that parameter value is invalid,
send an ABORT to peer with a Protocol Violation error code.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index c085472..fe2036d 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -3204,6 +3204,7 @@
 					sctp_cmd_seq_t *commands)
 {
 	struct sctp_chunk *chunk = arg;
+	sctp_errhdr_t *err;
 
 	if (!sctp_vtag_verify(chunk, asoc))
 		return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
@@ -3212,6 +3213,10 @@
 	if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
 		return sctp_sf_violation_chunklen(ep, asoc, type, arg,
 						  commands);
+	sctp_walk_errors(err, chunk->chunk_hdr);
+	if ((void *)err != (void *)chunk->chunk_end)
+		return sctp_sf_violation_paramlen(ep, asoc, type, arg,
+						  (void *)err, commands);
 
 	sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
 			SCTP_CHUNK(chunk));