From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: [PATCH v2 net-next 21/23] net/bridge: Update br_mdb_dump for strict data checking Date: Sun, 7 Oct 2018 20:16:42 -0700 Message-ID: <20181008031644.15989-22-dsahern@kernel.org> References: <20181008031644.15989-1-dsahern@kernel.org> Cc: christian@brauner.io, jbenc@redhat.com, stephen@networkplumber.org, David Ahern To: netdev@vger.kernel.org, davem@davemloft.net Return-path: Received: from mail.kernel.org ([198.145.29.99]:42626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727028AbeJHK0W (ORCPT ); Mon, 8 Oct 2018 06:26:22 -0400 In-Reply-To: <20181008031644.15989-1-dsahern@kernel.org> Sender: netdev-owner@vger.kernel.org List-ID: From: David Ahern Update br_mdb_dump for strict data checking. If the flag is set, the dump request is expected to have a br_port_msg struct as the header. All elements of the struct are expected to be 0 and no attributes can be appended. Signed-off-by: David Ahern --- net/bridge/br_mdb.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c index a4a848bf827b..a7ea2d431714 100644 --- a/net/bridge/br_mdb.c +++ b/net/bridge/br_mdb.c @@ -162,6 +162,29 @@ static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb, return err; } +static int br_mdb_valid_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct br_port_msg *bpm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*bpm))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for mdb dump request"); + return -EINVAL; + } + + bpm = nlmsg_data(nlh); + if (bpm->ifindex) { + NL_SET_ERR_MSG_MOD(extack, "Filtering by device index is not supported for mdb dump request"); + return -EINVAL; + } + if (nlmsg_attrlen(nlh, sizeof(*bpm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in mdb dump request"); + return -EINVAL; + } + + return 0; +} + static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb) { struct net_device *dev; @@ -169,6 +192,13 @@ static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb) struct nlmsghdr *nlh = NULL; int idx = 0, s_idx; + if (cb->strict_check) { + int err = br_mdb_valid_dump_req(cb->nlh, cb->extack); + + if (err < 0) + return err; + } + s_idx = cb->args[0]; rcu_read_lock(); -- 2.11.0