| Message ID | 20181004213355.14899-8-dsahern@kernel.org |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | rtnetlink: Add support for rigid checking of data in dump request | expand |
On Thu, Oct 04, 2018 at 02:33:42PM -0700, David Ahern wrote: > From: David Ahern <dsahern@gmail.com> > > Update inet6_dump_addr for strict data checking. If the flag is set, the > dump request is expected to have an ifaddrmsg struct as the header > potentially followed by one or more attributes. Any data passed in the > header or as an attribute is taken as a request to influence the data > returned. Only values suppored by the dump handler are allowed to be > non-0 or set in the request. At the moment only the IFA_TARGET_NETNSID > attribute is supported. Follow on patches can add support for other fields > (e.g., honor ifa_index and only return data for the given device index). > > Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Christian Brauner <christian@brauner.io> > --- > net/ipv6/addrconf.c | 51 ++++++++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 42 insertions(+), 9 deletions(-) > > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > index afa279170ba5..f749a3ad721a 100644 > --- a/net/ipv6/addrconf.c > +++ b/net/ipv6/addrconf.c > @@ -5001,6 +5001,8 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb, > static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, > enum addr_type_t type) > { > + struct netlink_ext_ack *extack = cb->extack; > + const struct nlmsghdr *nlh = cb->nlh; > struct inet6_fill_args fillargs = { > .portid = NETLINK_CB(cb->skb).portid, > .seq = cb->nlh->nlmsg_seq, > @@ -5009,7 +5011,6 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, > .type = type, > }; > struct net *net = sock_net(skb->sk); > - struct nlattr *tb[IFA_MAX+1]; > struct net *tgt_net = net; > int h, s_h; > int idx, ip_idx; > @@ -5022,15 +5023,47 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, > s_idx = idx = cb->args[1]; > s_ip_idx = ip_idx = cb->args[2]; > > - if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, > - ifa_ipv6_policy, cb->extack) >= 0) { > - if (tb[IFA_TARGET_NETNSID]) { > - fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); > + if (cb->strict_check) { > + struct nlattr *tb[IFA_MAX+1]; > + struct ifaddrmsg *ifm; > + int err, i; > + > + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { > + NL_SET_ERR_MSG(extack, "Invalid header"); > + return -EINVAL; > + } > + > + ifm = nlmsg_data(nlh); > + if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) { > + NL_SET_ERR_MSG(extack, "Invalid values in header for dump request"); > + return -EINVAL; > + } > + if (ifm->ifa_index) { > + NL_SET_ERR_MSG(extack, "Filter by device index not supported"); > + return -EINVAL; > + } > > - tgt_net = rtnl_get_net_ns_capable(skb->sk, > - fillargs.netnsid); > - if (IS_ERR(tgt_net)) > - return PTR_ERR(tgt_net); > + err = nlmsg_parse(nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, > + ifa_ipv6_policy, extack); > + if (err < 0) > + return err; > + > + for (i = 0; i <= IFA_MAX; ++i) { > + if (!tb[i]) > + continue; > + > + if (i == IFA_TARGET_NETNSID) { > + fillargs.netnsid = nla_get_s32(tb[i]); > + tgt_net = rtnl_get_net_ns_capable(skb->sk, > + fillargs.netnsid); > + if (IS_ERR(tgt_net)) { > + NL_SET_ERR_MSG(extack, "Invalid target namespace id"); > + return PTR_ERR(tgt_net); > + } > + } else { > + NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); > + return -EINVAL; > + } > } > } > > -- > 2.11.0 >
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index afa279170ba5..f749a3ad721a 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5001,6 +5001,8 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb, static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, enum addr_type_t type) { + struct netlink_ext_ack *extack = cb->extack; + const struct nlmsghdr *nlh = cb->nlh; struct inet6_fill_args fillargs = { .portid = NETLINK_CB(cb->skb).portid, .seq = cb->nlh->nlmsg_seq, @@ -5009,7 +5011,6 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, .type = type, }; struct net *net = sock_net(skb->sk); - struct nlattr *tb[IFA_MAX+1]; struct net *tgt_net = net; int h, s_h; int idx, ip_idx; @@ -5022,15 +5023,47 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb, s_idx = idx = cb->args[1]; s_ip_idx = ip_idx = cb->args[2]; - if (nlmsg_parse(cb->nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, - ifa_ipv6_policy, cb->extack) >= 0) { - if (tb[IFA_TARGET_NETNSID]) { - fillargs.netnsid = nla_get_s32(tb[IFA_TARGET_NETNSID]); + if (cb->strict_check) { + struct nlattr *tb[IFA_MAX+1]; + struct ifaddrmsg *ifm; + int err, i; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "Invalid header"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->ifa_prefixlen || ifm->ifa_flags || ifm->ifa_scope) { + NL_SET_ERR_MSG(extack, "Invalid values in header for dump request"); + return -EINVAL; + } + if (ifm->ifa_index) { + NL_SET_ERR_MSG(extack, "Filter by device index not supported"); + return -EINVAL; + } - tgt_net = rtnl_get_net_ns_capable(skb->sk, - fillargs.netnsid); - if (IS_ERR(tgt_net)) - return PTR_ERR(tgt_net); + err = nlmsg_parse(nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, + ifa_ipv6_policy, extack); + if (err < 0) + return err; + + for (i = 0; i <= IFA_MAX; ++i) { + if (!tb[i]) + continue; + + if (i == IFA_TARGET_NETNSID) { + fillargs.netnsid = nla_get_s32(tb[i]); + tgt_net = rtnl_get_net_ns_capable(skb->sk, + fillargs.netnsid); + if (IS_ERR(tgt_net)) { + NL_SET_ERR_MSG(extack, "Invalid target namespace id"); + return PTR_ERR(tgt_net); + } + } else { + NL_SET_ERR_MSG(extack, "Unsupported attribute in dump request"); + return -EINVAL; + } } }