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 <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index e38e1f1..f6d2609 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;
