On Thu, Oct 04, 2018 at 02:33:54PM -0700, David Ahern wrote:
> From: David Ahern <dsah...@gmail.com>
>
> Update inet_netconf_dump_devconf, inet6_netconf_dump_devconf, and
> mpls_netconf_dump_devconf for strict data checking. If the flag is set,
> the dump request is expected to have an netconfmsg struct as the header.
> The struct only has the family member and no attributes can be appended.
>
> Signed-off-by: David Ahern <dsah...@gmail.com>
Acked-by: Christian Brauner <christ...@brauner.io>
> ---
> net/ipv4/devinet.c | 22 +++++++++++++++++++---
> net/ipv6/addrconf.c | 22 +++++++++++++++++++---
> net/mpls/af_mpls.c | 18 +++++++++++++++++-
> 3 files changed, 55 insertions(+), 7 deletions(-)
>
> diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
> index af968d4fe4fc..595706d6b672 100644
> --- a/net/ipv4/devinet.c
> +++ b/net/ipv4/devinet.c
> @@ -2069,6 +2069,7 @@ static int inet_netconf_get_devconf(struct sk_buff
> *in_skb,
> static int inet_netconf_dump_devconf(struct sk_buff *skb,
> struct netlink_callback *cb)
> {
> + const struct nlmsghdr *nlh = cb->nlh;
> struct net *net = sock_net(skb->sk);
> int h, s_h;
> int idx, s_idx;
> @@ -2076,6 +2077,21 @@ static int inet_netconf_dump_devconf(struct sk_buff
> *skb,
> struct in_device *in_dev;
> struct hlist_head *head;
>
> + if (cb->strict_check) {
> + struct netlink_ext_ack *extack = cb->extack;
> + struct netconfmsg *ncm;
> +
> + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
> + NL_SET_ERR_MSG(extack, "Invalid header");
> + return -EINVAL;
> + }
> +
> + if (nlh->nlmsg_len != nlmsg_msg_size(sizeof(*ncm))) {
> + NL_SET_ERR_MSG(extack, "Invalid data after header");
> + return -EINVAL;
> + }
Hm, I think this could just be one branch with !=
But if you've done this to report back a more meaningful error message
to userspace, fine. :)
> + }
> +
> s_h = cb->args[0];
> s_idx = idx = cb->args[1];
>
> @@ -2095,7 +2111,7 @@ static int inet_netconf_dump_devconf(struct sk_buff
> *skb,
> if (inet_netconf_fill_devconf(skb, dev->ifindex,
> &in_dev->cnf,
>
> NETLINK_CB(cb->skb).portid,
> - cb->nlh->nlmsg_seq,
> + nlh->nlmsg_seq,
> RTM_NEWNETCONF,
> NLM_F_MULTI,
> NETCONFA_ALL) < 0) {
> @@ -2112,7 +2128,7 @@ static int inet_netconf_dump_devconf(struct sk_buff
> *skb,
> if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
> net->ipv4.devconf_all,
> NETLINK_CB(cb->skb).portid,
> - cb->nlh->nlmsg_seq,
> + nlh->nlmsg_seq,
> RTM_NEWNETCONF, NLM_F_MULTI,
> NETCONFA_ALL) < 0)
> goto done;
> @@ -2123,7 +2139,7 @@ static int inet_netconf_dump_devconf(struct sk_buff
> *skb,
> if (inet_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
> net->ipv4.devconf_dflt,
> NETLINK_CB(cb->skb).portid,
> - cb->nlh->nlmsg_seq,
> + nlh->nlmsg_seq,
> RTM_NEWNETCONF, NLM_F_MULTI,
> NETCONFA_ALL) < 0)
> goto done;
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index 693199a29426..9dfe6c2106c1 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -666,6 +666,7 @@ static int inet6_netconf_get_devconf(struct sk_buff
> *in_skb,
> static int inet6_netconf_dump_devconf(struct sk_buff *skb,
> struct netlink_callback *cb)
> {
> + const struct nlmsghdr *nlh = cb->nlh;
> struct net *net = sock_net(skb->sk);
> int h, s_h;
> int idx, s_idx;
> @@ -673,6 +674,21 @@ static int inet6_netconf_dump_devconf(struct sk_buff
> *skb,
> struct inet6_dev *idev;
> struct hlist_head *head;
>
> + if (cb->strict_check) {
> + struct netlink_ext_ack *extack = cb->extack;
> + struct netconfmsg *ncm;
> +
> + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
> + NL_SET_ERR_MSG(extack, "Invalid header");
> + return -EINVAL;
> + }
> +
> + if (nlh->nlmsg_len != nlmsg_msg_size(sizeof(*ncm))) {
> + NL_SET_ERR_MSG(extack, "Invalid data after header");
> + return -EINVAL;
> + }
> + }
> +
> s_h = cb->args[0];
> s_idx = idx = cb->args[1];
>
> @@ -692,7 +708,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb,
> if (inet6_netconf_fill_devconf(skb, dev->ifindex,
> &idev->cnf,
>
> NETLINK_CB(cb->skb).portid,
> - cb->nlh->nlmsg_seq,
> + nlh->nlmsg_seq,
> RTM_NEWNETCONF,
> NLM_F_MULTI,
> NETCONFA_ALL) < 0) {
> @@ -709,7 +725,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb,
> if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_ALL,
> net->ipv6.devconf_all,
> NETLINK_CB(cb->skb).portid,
> - cb->nlh->nlmsg_seq,
> + nlh->nlmsg_seq,
> RTM_NEWNETCONF, NLM_F_MULTI,
> NETCONFA_ALL) < 0)
> goto done;
> @@ -720,7 +736,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb,
> if (inet6_netconf_fill_devconf(skb, NETCONFA_IFINDEX_DEFAULT,
> net->ipv6.devconf_dflt,
> NETLINK_CB(cb->skb).portid,
> - cb->nlh->nlmsg_seq,
> + nlh->nlmsg_seq,
> RTM_NEWNETCONF, NLM_F_MULTI,
> NETCONFA_ALL) < 0)
> goto done;
> diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
> index 3e33934751b4..b80b00b55bdf 100644
> --- a/net/mpls/af_mpls.c
> +++ b/net/mpls/af_mpls.c
> @@ -1263,6 +1263,7 @@ static int mpls_netconf_get_devconf(struct sk_buff
> *in_skb,
> static int mpls_netconf_dump_devconf(struct sk_buff *skb,
> struct netlink_callback *cb)
> {
> + const struct nlmsghdr *nlh = cb->nlh;
> struct net *net = sock_net(skb->sk);
> struct hlist_head *head;
> struct net_device *dev;
> @@ -1270,6 +1271,21 @@ static int mpls_netconf_dump_devconf(struct sk_buff
> *skb,
> int idx, s_idx;
> int h, s_h;
>
> + if (cb->strict_check) {
> + struct netlink_ext_ack *extack = cb->extack;
> + struct netconfmsg *ncm;
> +
> + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
> + NL_SET_ERR_MSG(extack, "Invalid header");
> + return -EINVAL;
> + }
> +
> + if (nlh->nlmsg_len != nlmsg_msg_size(sizeof(*ncm))) {
> + NL_SET_ERR_MSG(extack, "Invalid data after header");
> + return -EINVAL;
> + }
> + }
> +
> s_h = cb->args[0];
> s_idx = idx = cb->args[1];
>
> @@ -1286,7 +1302,7 @@ static int mpls_netconf_dump_devconf(struct sk_buff
> *skb,
> goto cont;
> if (mpls_netconf_fill_devconf(skb, mdev,
>
> NETLINK_CB(cb->skb).portid,
> - cb->nlh->nlmsg_seq,
> + nlh->nlmsg_seq,
> RTM_NEWNETCONF,
> NLM_F_MULTI,
> NETCONFA_ALL) < 0) {
> --
> 2.11.0
>
