From af8a2b8ba7678b4695f9e854ba9abae1076beabe Mon Sep 17 00:00:00 2001 From: Xin Long Date: Mon, 3 Sep 2018 15:47:10 +0800 Subject: [PATCH] sctp: fix invalid reference to the index variable of the iterator Now in sctp_apply_peer_addr_params(), if SPP_IPV6_FLOWLABEL flag is set and trans is NULL, it would use trans as the index variable to traverse transport_addr_list, then trans is set as the last transport of it. Later, if SPP_DSCP flag is set, it would enter into the wrong branch as trans is actually an invalid reference. So fix it by using a new index variable to traverse transport_addr_list for both SPP_DSCP and SPP_IPV6_FLOWLABEL flags process. Fixes: 0b0dce7a36fb ("sctp: add spp_ipv6_flowlabel and spp_dscp for sctp_paddrparams") Reported-by: Julia Lawall Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/sctp/socket.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index aa76586a1a1c..a0ccfa4b8220 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2663,14 +2663,15 @@ static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params, SCTP_FLOWLABEL_VAL_MASK; trans->flowlabel |= SCTP_FLOWLABEL_SET_MASK; } else if (asoc) { - list_for_each_entry(trans, - &asoc->peer.transport_addr_list, + struct sctp_transport *t; + + list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) { - if (trans->ipaddr.sa.sa_family != AF_INET6) + if (t->ipaddr.sa.sa_family != AF_INET6) continue; - trans->flowlabel = params->spp_ipv6_flowlabel & - SCTP_FLOWLABEL_VAL_MASK; - trans->flowlabel |= SCTP_FLOWLABEL_SET_MASK; + t->flowlabel = params->spp_ipv6_flowlabel & + SCTP_FLOWLABEL_VAL_MASK; + t->flowlabel |= SCTP_FLOWLABEL_SET_MASK; } asoc->flowlabel = params->spp_ipv6_flowlabel & SCTP_FLOWLABEL_VAL_MASK; @@ -2687,12 +2688,13 @@ static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params, trans->dscp = params->spp_dscp & SCTP_DSCP_VAL_MASK; trans->dscp |= SCTP_DSCP_SET_MASK; } else if (asoc) { - list_for_each_entry(trans, - &asoc->peer.transport_addr_list, + struct sctp_transport *t; + + list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) { - trans->dscp = params->spp_dscp & - SCTP_DSCP_VAL_MASK; - trans->dscp |= SCTP_DSCP_SET_MASK; + t->dscp = params->spp_dscp & + SCTP_DSCP_VAL_MASK; + t->dscp |= SCTP_DSCP_SET_MASK; } asoc->dscp = params->spp_dscp & SCTP_DSCP_VAL_MASK; asoc->dscp |= SCTP_DSCP_SET_MASK; -- 2.30.2