[PATCH net-next 18/20] net/ipv6: Update ip6addrlbl_dump for strict data checking
From: David Ahern <dsahern@kernel.org>
Date: 2018-10-05 04:29:17
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
From: David Ahern <redacted> Update ip6addrlbl_dump for strict data checking. If the flag is set, the dump request is expected to have an ifaddrlblmsg 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 <redacted> --- net/ipv6/addrlabel.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
index 1d6ced37ad71..10556049cc44 100644
--- a/net/ipv6/addrlabel.c
+++ b/net/ipv6/addrlabel.c@@ -458,20 +458,53 @@ static int ip6addrlbl_fill(struct sk_buff *skb, return 0; } +static int ip6addrlbl_valid_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ifaddrlblmsg *ifal; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifal))) { + NL_SET_ERR_MSG(extack, "Invalid header"); + return -EINVAL; + } + + ifal = nlmsg_data(nlh); + if (ifal->__ifal_reserved || ifal->ifal_prefixlen || + ifal->ifal_flags || ifal->ifal_index || ifal->ifal_seq) { + NL_SET_ERR_MSG(extack, + "Invalid values in header for dump request"); + return -EINVAL; + } + + if (nlh->nlmsg_len != nlmsg_msg_size(sizeof(*ifal))) { + NL_SET_ERR_MSG(extack, "Invalid data after header"); + return -EINVAL; + } + + return 0; +} + static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct ip6addrlbl_entry *p; int idx = 0, s_idx = cb->args[0]; int err; + if (cb->strict_check) { + err = ip6addrlbl_valid_dump_req(nlh, cb->extack); + if (err) + return err; + } + rcu_read_lock(); hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) { if (idx >= s_idx) { err = ip6addrlbl_fill(skb, p, net->ipv6.ip6addrlbl_table.seq, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWADDRLABEL, NLM_F_MULTI); if (err < 0)
--
2.11.0