From 5f729eaabef9308cfaa4b27c9b3f120253eff79b Mon Sep 17 00:00:00 2001 From: Julien Gomes Date: Tue, 20 Jun 2017 13:54:16 -0700 Subject: [PATCH] rtnetlink: add restricted rtnl groups for ipv4 and ipv6 mroute Add RTNLGRP_{IPV4,IPV6}_MROUTE_R as two new restricted groups for the NETLINK_ROUTE family. Binding to these groups specifically requires CAP_NET_ADMIN to allow multicast of sensitive messages (e.g. mroute cache reports). Suggested-by: Nikolay Aleksandrov Signed-off-by: Julien Gomes Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- include/uapi/linux/rtnetlink.h | 4 ++++ net/core/rtnetlink.c | 13 +++++++++++++ 2 files changed, 17 insertions(+) diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index cd1afb900929..d148505010a7 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -669,6 +669,10 @@ enum rtnetlink_groups { #define RTNLGRP_NSID RTNLGRP_NSID RTNLGRP_MPLS_NETCONF, #define RTNLGRP_MPLS_NETCONF RTNLGRP_MPLS_NETCONF + RTNLGRP_IPV4_MROUTE_R, +#define RTNLGRP_IPV4_MROUTE_R RTNLGRP_IPV4_MROUTE_R + RTNLGRP_IPV6_MROUTE_R, +#define RTNLGRP_IPV6_MROUTE_R RTNLGRP_IPV6_MROUTE_R __RTNLGRP_MAX }; #define RTNLGRP_MAX (__RTNLGRP_MAX - 1) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 3aa57848a895..4aefa5a2625f 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4218,6 +4218,18 @@ static void rtnetlink_rcv(struct sk_buff *skb) rtnl_unlock(); } +static int rtnetlink_bind(struct net *net, int group) +{ + switch (group) { + case RTNLGRP_IPV4_MROUTE_R: + case RTNLGRP_IPV6_MROUTE_R: + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + break; + } + return 0; +} + static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); @@ -4252,6 +4264,7 @@ static int __net_init rtnetlink_net_init(struct net *net) .input = rtnetlink_rcv, .cb_mutex = &rtnl_mutex, .flags = NL_CFG_F_NONROOT_RECV, + .bind = rtnetlink_bind, }; sk = netlink_kernel_create(net, NETLINK_ROUTE, &cfg); -- 2.45.2