[UDP]: Do not allow specific bind when wildcard bind exists.

When allocating local ports, do not allow a bind to a port
with a specific local address when a bind to that port with
a wildcard local address already exists.

Noticed by Linus.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 8 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index db313d964884..113e0c4c8a92 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -203,6 +203,13 @@ int __udp_lib_get_port(struct sock *sk, unsigned short snum,
                                 result = sysctl_local_port_range[0]
                                         + ((result - sysctl_local_port_range[0]) &
                                            (UDP_HTABLE_SIZE - 1));
+                        hash = hash_port_and_addr(result, 0);
+                        if (__udp_lib_port_inuse(hash, result,
+                                                 0, udptable))
+                                continue;
+                        if (!inet_sk(sk)->rcv_saddr)
+                                break;
+
                         hash = hash_port_and_addr(result,
                                         inet_sk(sk)->rcv_saddr);
                         if (! __udp_lib_port_inuse(hash, result,
@@ -214,18 +221,36 @@ int __udp_lib_get_port(struct sock *sk, unsigned short snum,
 gotit:
                 *port_rover = snum = result;
         } else {
-                hash = hash_port_and_addr(snum, inet_sk(sk)->rcv_saddr);
+                hash = hash_port_and_addr(snum, 0);
                 head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
 
                 sk_for_each(sk2, node, head)
-                        if (sk2->sk_hash == hash                             &&
-                            sk2 != sk                                        &&
-                            inet_sk(sk2)->num == snum                        &&
-                            (!sk2->sk_reuse        || !sk->sk_reuse)         &&
-                            (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
-                             || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
-                            (*saddr_comp)(sk, sk2)                             )
+                        if (sk2->sk_hash == hash &&
+                            sk2 != sk &&
+                            inet_sk(sk2)->num == snum &&
+                            (!sk2->sk_reuse || !sk->sk_reuse) &&
+                            (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
+                             sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+                            (*saddr_comp)(sk, sk2))
                                 goto fail;
+
+                if (inet_sk(sk)->rcv_saddr) {
+                        hash = hash_port_and_addr(snum,
+                                                  inet_sk(sk)->rcv_saddr);
+                        head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
+
+                        sk_for_each(sk2, node, head)
+                                if (sk2->sk_hash == hash &&
+                                    sk2 != sk &&
+                                    inet_sk(sk2)->num == snum &&
+                                    (!sk2->sk_reuse || !sk->sk_reuse) &&
+                                    (!sk2->sk_bound_dev_if ||
+                                     !sk->sk_bound_dev_if ||
+                                     sk2->sk_bound_dev_if ==
+                                     sk->sk_bound_dev_if) &&
+                                    (*saddr_comp)(sk, sk2))
+                                        goto fail;
+                }
         }
         inet_sk(sk)->num = snum;
         sk->sk_hash = hash;