From f2ae64bb6ba5b6a6e2271094a03d098821f4a699 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:40 -0700 Subject: [PATCH] net/ipv6: Update ip6addrlbl_dump for strict data checking 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 Acked-by: Christian Brauner Signed-off-by: David S. Miller --- net/ipv6/addrlabel.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c index 1d6ced37ad71..0d1ee82ee55b 100644 --- a/net/ipv6/addrlabel.c +++ b/net/ipv6/addrlabel.c @@ -458,20 +458,52 @@ 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_MOD(extack, "Invalid header for address label dump request"); + 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_MOD(extack, "Invalid values in header for address label dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ifal))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid data after header for address label dump requewst"); + 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 < 0) + 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)