From 9632d47f6a88f7f075347b66b88c60df7e9eae05 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:37 -0700 Subject: [PATCH] net/neighbor: Update neightbl_dump_info for strict data checking Update neightbl_dump_info for strict data checking. If the flag is set, the dump request is expected to have an ndtmsg 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/core/neighbour.c | 38 +++++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 7c8a3a0..dc1389b 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -2164,15 +2164,47 @@ errout: return err; } +static int neightbl_valid_dump_info(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ndtmsg *ndtm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ndtm))) { + NL_SET_ERR_MSG(extack, "Invalid header for neighbor table dump request"); + return -EINVAL; + } + + ndtm = nlmsg_data(nlh); + if (ndtm->ndtm_pad1 || ndtm->ndtm_pad2) { + NL_SET_ERR_MSG(extack, "Invalid values in header for neighbor table dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ndtm))) { + NL_SET_ERR_MSG(extack, "Invalid data after header in neighbor table dump request"); + return -EINVAL; + } + + return 0; +} + static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); int family, tidx, nidx = 0; int tbl_skip = cb->args[0]; int neigh_skip = cb->args[1]; struct neigh_table *tbl; - family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family; + if (cb->strict_check) { + int err = neightbl_valid_dump_info(nlh, cb->extack); + + if (err < 0) + return err; + } + + family = ((struct rtgenmsg *)nlmsg_data(nlh))->rtgen_family; for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) { struct neigh_parms *p; @@ -2185,7 +2217,7 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) continue; if (neightbl_fill_info(skb, tbl, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, RTM_NEWNEIGHTBL, + nlh->nlmsg_seq, RTM_NEWNEIGHTBL, NLM_F_MULTI) < 0) break; @@ -2200,7 +2232,7 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) if (neightbl_fill_param_info(skb, tbl, p, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, + nlh->nlmsg_seq, RTM_NEWNEIGHTBL, NLM_F_MULTI) < 0) goto out; -- 2.7.4