diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 12fd52105005..e38e1f178611 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4021,28 +4021,72 @@ int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq, } EXPORT_SYMBOL_GPL(ndo_dflt_bridge_getlink); +static int valid_bridge_getlink_req(const struct nlmsghdr *nlh, + bool strict_check, u32 *filter_mask, + struct netlink_ext_ack *extack) +{ + struct nlattr *tb[IFLA_MAX+1]; + int err, i; + + if (strict_check) { + struct ifinfomsg *ifm; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) { + NL_SET_ERR_MSG(extack, "Invalid header for bridge link dump"); + return -EINVAL; + } + + ifm = nlmsg_data(nlh); + if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags || + ifm->ifi_change || ifm->ifi_index) { + NL_SET_ERR_MSG(extack, "Invalid values in header for bridge link dump request"); + return -EINVAL; + } + + err = nlmsg_parse_strict(nlh, sizeof(struct ifinfomsg), tb, + IFLA_MAX, ifla_policy, extack); + } else { + err = nlmsg_parse(nlh, sizeof(struct ifinfomsg), tb, + IFLA_MAX, ifla_policy, extack); + } + if (err < 0) + return err; + + /* new attributes should only be added with strict checking */ + for (i = 0; i <= IFLA_MAX; ++i) { + if (!tb[i]) + continue; + + switch (i) { + case IFLA_EXT_MASK: + *filter_mask = nla_get_u32(tb[i]); + break; + default: + if (strict_check) { + NL_SET_ERR_MSG(extack, "Unsupported attribute in bridge link dump request"); + return -EINVAL; + } + } + } + + return 0; +} + static int rtnl_bridge_getlink(struct sk_buff *skb, struct netlink_callback *cb) { + const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct net_device *dev; int idx = 0; u32 portid = NETLINK_CB(cb->skb).portid; - u32 seq = cb->nlh->nlmsg_seq; + u32 seq = nlh->nlmsg_seq; u32 filter_mask = 0; int err; - if (nlmsg_len(cb->nlh) > sizeof(struct ifinfomsg)) { - struct nlattr *extfilt; - - extfilt = nlmsg_find_attr(cb->nlh, sizeof(struct ifinfomsg), - IFLA_EXT_MASK); - if (extfilt) { - if (nla_len(extfilt) < sizeof(filter_mask)) - return -EINVAL; - - filter_mask = nla_get_u32(extfilt); - } - } + err = valid_bridge_getlink_req(nlh, cb->strict_check, &filter_mask, + cb->extack); + if (err < 0 && cb->strict_check) + return err; rcu_read_lock(); for_each_netdev_rcu(net, dev) {