From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: [PATCH net-next 11/20] rtnetlink: Update inet6_dump_ifinfo for strict data checking Date: Thu, 4 Oct 2018 14:33:46 -0700 Message-ID: <20181004213355.14899-12-dsahern@kernel.org> References: <20181004213355.14899-1-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]:37664 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728141AbeJEE3P (ORCPT ); Fri, 5 Oct 2018 00:29:15 -0400 In-Reply-To: <20181004213355.14899-1-dsahern@kernel.org> Sender: netdev-owner@vger.kernel.org List-ID: From: David Ahern Update inet6_dump_ifinfo for strict data checking. If the flag is set, the dump request is expected to have an ifinfomsg 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/ipv6/addrconf.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index f749a3ad721a..693199a29426 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5628,6 +5628,31 @@ static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev, return -EMSGSIZE; } +static int inet6_valid_dump_ifinfo(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ifinfomsg *ifm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "Invalid header"); + return -EINVAL; + } + + if (nlh->nlmsg_len > nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags || + ifm->ifi_change || ifm->ifi_index) { + NL_SET_ERR_MSG(extack, "Invalid values in header for dump request"); + return -EINVAL; + } + + return 0; +} + static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); @@ -5637,6 +5662,16 @@ static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) struct inet6_dev *idev; struct hlist_head *head; + /* only requests using strict checking can pass data to + * influence the dump + */ + if (cb->strict_check) { + int err = inet6_valid_dump_ifinfo(cb->nlh, cb->extack); + + if (err) + return err; + } + s_h = cb->args[0]; s_idx = cb->args[1]; -- 2.11.0