From 841891ec0c65d9ec81b3c56975d61ecc5b6ca365 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:32 -0700 Subject: [PATCH] rtnetlink: Update rtnl_stats_dump for strict data checking Update rtnl_stats_dump for strict data checking. If the flag is set, the dump request is expected to have an if_stats_msg struct as the header. All elements of the struct are expected to be 0 except filter_mask which must be non-0 (legacy behavior). No attributes are supported. Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index e38e1f178611..f6d2609cfa9f 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4680,6 +4680,7 @@ static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh, static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb) { + struct netlink_ext_ack *extack = cb->extack; int h, s_h, err, s_idx, s_idxattr, s_prividx; struct net *net = sock_net(skb->sk); unsigned int flags = NLM_F_MULTI; @@ -4696,13 +4697,32 @@ static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb) cb->seq = net->dev_base_seq; - if (nlmsg_len(cb->nlh) < sizeof(*ifsm)) + if (nlmsg_len(cb->nlh) < sizeof(*ifsm)) { + NL_SET_ERR_MSG(extack, "Invalid header for stats dump"); return -EINVAL; + } ifsm = nlmsg_data(cb->nlh); + + /* only requests using NLM_F_DUMP_PROPER_HDR can pass data to + * influence the dump. The legacy exception is filter_mask. + */ + if (cb->strict_check) { + if (ifsm->pad1 || ifsm->pad2 || ifsm->ifindex) { + NL_SET_ERR_MSG(extack, "Invalid values in header for stats dump request"); + return -EINVAL; + } + if (nlmsg_attrlen(cb->nlh, sizeof(*ifsm))) { + NL_SET_ERR_MSG(extack, "Invalid attributes after stats header"); + return -EINVAL; + } + } + filter_mask = ifsm->filter_mask; - if (!filter_mask) + if (!filter_mask) { + NL_SET_ERR_MSG(extack, "Filter mask must be set for stats dump"); return -EINVAL; + } for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { idx = 0; -- 2.11.0