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authorShawn Bohrer <sbohrer@rgmadvisors.com>2015-06-03 16:27:38 -0500
committerDavid S. Miller <davem@davemloft.net>2015-06-04 00:46:26 -0700
commit6e540309326188f769e03bb4c6dd8ff6752930c2 (patch)
tree5e024fab9cf5bd0affa537c2c04389daa551d022 /net
parent640b2b107cec23c754214b62a811465fa8f9257f (diff)
downloadlinux-linaro-stable-6e540309326188f769e03bb4c6dd8ff6752930c2.tar.gz
ipv4/udp: Verify multicast group is ours in upd_v4_early_demux()
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@rgmadvisors.com> Reported-by: Yurij M. Plotnikov <Yurij.Plotnikov@oktetlabs.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/udp.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 1c92ea67baef..83aa604f9273 100644
--- 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>
@@ -1960,6 +1961,7 @@ void udp_v4_early_demux(struct sk_buff *skb)
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)))
@@ -1969,14 +1971,24 @@ void udp_v4_early_demux(struct sk_buff *skb)
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;