Commit 0bd84065 authored by subashab@codeaurora.org's avatar subashab@codeaurora.org Committed by David S. Miller

net: ipv6: Fix UDP early demux lookup with udp_l3mdev_accept=0

David Ahern reported that 5425077d ("net: ipv6: Add early demux
handler for UDP unicast") breaks udp_l3mdev_accept=0 since early
demux for IPv6 UDP was doing a generic socket lookup which does not
require an exact match. Fix this by making UDPv6 early demux match
connected sockets only.

v1->v2: Take reference to socket after match as suggested by Eric
v2->v3: Add comment before break

Fixes: 5425077d ("net: ipv6: Add early demux handler for UDP unicast")
Reported-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: default avatarSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Tested-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8ad0921b
...@@ -46,6 +46,7 @@ ...@@ -46,6 +46,7 @@
#include <net/tcp_states.h> #include <net/tcp_states.h>
#include <net/ip6_checksum.h> #include <net/ip6_checksum.h>
#include <net/xfrm.h> #include <net/xfrm.h>
#include <net/inet_hashtables.h>
#include <net/inet6_hashtables.h> #include <net/inet6_hashtables.h>
#include <net/busy_poll.h> #include <net/busy_poll.h>
#include <net/sock_reuseport.h> #include <net/sock_reuseport.h>
...@@ -864,21 +865,26 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, ...@@ -864,21 +865,26 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
return 0; return 0;
} }
static struct sock *__udp6_lib_demux_lookup(struct net *net, static struct sock *__udp6_lib_demux_lookup(struct net *net,
__be16 loc_port, const struct in6_addr *loc_addr, __be16 loc_port, const struct in6_addr *loc_addr,
__be16 rmt_port, const struct in6_addr *rmt_addr, __be16 rmt_port, const struct in6_addr *rmt_addr,
int dif) int dif)
{ {
unsigned short hnum = ntohs(loc_port);
unsigned int hash2 = udp6_portaddr_hash(net, loc_addr, hnum);
unsigned int slot2 = hash2 & udp_table.mask;
struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
struct sock *sk; struct sock *sk;
rcu_read_lock(); udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
sk = __udp6_lib_lookup(net, rmt_addr, rmt_port, loc_addr, loc_port, if (INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif))
dif, &udp_table, NULL); return sk;
if (sk && !atomic_inc_not_zero(&sk->sk_refcnt)) /* Only check first socket in chain */
sk = NULL; break;
rcu_read_unlock(); }
return NULL;
return sk;
} }
static void udp_v6_early_demux(struct sk_buff *skb) static void udp_v6_early_demux(struct sk_buff *skb)
...@@ -903,7 +909,7 @@ static void udp_v6_early_demux(struct sk_buff *skb) ...@@ -903,7 +909,7 @@ static void udp_v6_early_demux(struct sk_buff *skb)
else else
return; return;
if (!sk) if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2))
return; return;
skb->sk = sk; skb->sk = sk;
......
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