sctp: sctp_sendmsg: Don't initialize default_sinfo

This variable only needs initialization when cmsgs.info
is NULL.

Use memset to ensure padding is also zeroed so
kernel doesn't leak any data.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/socket.c

@@ -1496,7 +1496,7 @@ SCTP_STATIC int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
 	struct sctp_chunk *chunk;
 	union sctp_addr to;
 	struct sockaddr *msg_name = NULL;
-	struct sctp_sndrcvinfo default_sinfo = { 0 };
+	struct sctp_sndrcvinfo default_sinfo;
 	struct sctp_sndrcvinfo *sinfo;
 	struct sctp_initmsg *sinit;
 	sctp_assoc_t associd = 0;
@@ -1760,6 +1760,7 @@ SCTP_STATIC int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
 		/* If the user didn't specify SNDRCVINFO, make up one with
 		 * some defaults.
 		 */
+		memset(&default_sinfo, 0, sizeof(default_sinfo));
 		default_sinfo.sinfo_stream = asoc->default_stream;
 		default_sinfo.sinfo_flags = asoc->default_flags;
 		default_sinfo.sinfo_ppid = asoc->default_ppid;