[PATCH net-next 10/20] rtnetlink: Update rtnl_stats_dump for strict data checking
From: David Ahern <dsahern@kernel.org>
Date: 2018-10-05 04:29:15
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: David Ahern <redacted> 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 <redacted> --- 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 d2c8d41a6fbc..6cdd9251771a 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c@@ -4643,6 +4643,7 @@ 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;
@@ -4659,13 +4660,32 @@ 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"); 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 dump request"); + return -EINVAL; + } + if (cb->nlh->nlmsg_len > nlmsg_msg_size(sizeof(*ifsm))) { + NL_SET_ERR_MSG(extack, "Invalid attributes after header"); + return -EINVAL; + } + } + filter_mask = ifsm->filter_mask; - if (!filter_mask) + if (!filter_mask) { + NL_SET_ERR_MSG(extack, "Invalid filter_mask"); return -EINVAL; + } for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { idx = 0;
--
2.11.0