sctp: allow setting SCTP_SACK_IMMEDIATELY by the application

commit 27f7ed2b11d42ab6d796e96533c2076ec220affc upstream.

This patch extends commit b93d6471748d ("sctp: implement the sender side
for SACK-IMMEDIATELY extension") as it didn't white list
SCTP_SACK_IMMEDIATELY on sctp_msghdr_parse(), causing it to be
understood as an invalid flag and returning -EINVAL to the application.

Note that the actual handling of the flag is already there in
sctp_datamsg_from_user().

https://tools.ietf.org/html/rfc7053#section-7

Fixes: b93d6471748d ("sctp: implement the sender side for SACK-IMMEDIATELY extension")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: drop the second hunk as we don't have SCTP_SNDINFO
 cmsg support]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 396283b..bb8c3b4 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6241,6 +6241,7 @@ SCTP_STATIC int sctp_msghdr_parse(const struct msghdr *msg,
                        /* Minimally, validate the sinfo_flags. */
                        if (cmsgs->info->sinfo_flags &
                            ~(SCTP_UNORDERED | SCTP_ADDR_OVER |
                        /* Minimally, validate the sinfo_flags. */
                        if (cmsgs->info->sinfo_flags &
                            ~(SCTP_UNORDERED | SCTP_ADDR_OVER |

+                             SCTP_SACK_IMMEDIATELY |

                              SCTP_ABORT | SCTP_EOF))
                                return -EINVAL;
                        break;
                              SCTP_ABORT | SCTP_EOF))
                                return -EINVAL;
                        break;