This is a note to let you know that I've just added the patch titled ipv4/udp: Verify multicast group is ours in upd_v4_early_demux() to the 4.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv4-udp-verify-multicast-group-is-ours-in-upd_v4_early_demux.patch and it can be found in the queue-4.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Jun 13 09:48:35 PDT 2015 From: Shawn Bohrer <sbohrer@xxxxxxxxxxxxxxx> Date: Wed, 3 Jun 2015 16:27:38 -0500 Subject: ipv4/udp: Verify multicast group is ours in upd_v4_early_demux() From: Shawn Bohrer <sbohrer@xxxxxxxxxxxxxxx> [ Upstream commit 6e540309326188f769e03bb4c6dd8ff6752930c2 ] 421b3885bf6d56391297844f43fb7154a6396e12 "udp: ipv4: Add udp early demux" introduced a regression that allowed sockets bound to INADDR_ANY to receive packets from multicast groups that the socket had not joined. For example a socket that had joined 224.168.2.9 could also receive packets from 225.168.2.9 despite not having joined that group if ip_early_demux is enabled. Fix this by calling ip_check_mc_rcu() in udp_v4_early_demux() to verify that the multicast packet is indeed ours. Signed-off-by: Shawn Bohrer <sbohrer@xxxxxxxxxxxxxxx> Reported-by: Yurij M. Plotnikov <Yurij.Plotnikov@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/udp.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -90,6 +90,7 @@ #include <linux/socket.h> #include <linux/sockios.h> #include <linux/igmp.h> +#include <linux/inetdevice.h> #include <linux/in.h> #include <linux/errno.h> #include <linux/timer.h> @@ -1966,6 +1967,7 @@ void udp_v4_early_demux(struct sk_buff * struct sock *sk; struct dst_entry *dst; int dif = skb->dev->ifindex; + int ours; /* validate the packet */ if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr))) @@ -1975,14 +1977,24 @@ void udp_v4_early_demux(struct sk_buff * uh = udp_hdr(skb); if (skb->pkt_type == PACKET_BROADCAST || - skb->pkt_type == PACKET_MULTICAST) + skb->pkt_type == PACKET_MULTICAST) { + struct in_device *in_dev = __in_dev_get_rcu(skb->dev); + + if (!in_dev) + return; + + ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr, + iph->protocol); + if (!ours) + return; sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr, uh->source, iph->saddr, dif); - else if (skb->pkt_type == PACKET_HOST) + } else if (skb->pkt_type == PACKET_HOST) { sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, uh->source, iph->saddr, dif); - else + } else { return; + } if (!sk) return; Patches currently in stable-queue which might be from sbohrer@xxxxxxxxxxxxxxx are queue-4.0/ipv4-udp-verify-multicast-group-is-ours-in-upd_v4_early_demux.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html