udp_diag: Fix socket skipping within chain

commit 86f3cddbc3037882414c7308973530167906b7e9 upstream.

While working on rhashtable walking I noticed that the UDP diag
dumping code is buggy.  In particular, the socket skipping within
a chain never happens, even though we record the number of sockets
that should be skipped.

As this code was supposedly copied from TCP, this patch does what
TCP does and resets num before we walk a chain.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c
index 7927db0a927951a20b4502d38fca0bba9e94862c..4a000f1dd75753833b792f6979bf697337f4dd7a 100644 (file)
--- a/net/ipv4/udp_diag.c
+++ b/net/ipv4/udp_diag.c
@@ -99,11 +99,13 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlin
        s_slot = cb->args[0];
        num = s_num = cb->args[1];
 
-       for (slot = s_slot; slot <= table->mask; num = s_num = 0, slot++) {
+       for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
                struct sock *sk;
                struct hlist_nulls_node *node;
                struct udp_hslot *hslot = &table->hash[slot];
 
+               num = 0;
+
                if (hlist_nulls_empty(&hslot->head))
                        continue;