[IPV6]: Fix rtnetlink dump infinite loop

The recent change to netlink dump "done" callback handling broke IPv6
which played dirty tricks with the "done" callback.  This causes an
infinite loop during a dump.

The following patch fixes it.

This bug was reported by Jeff Garzik.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 4 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index f7f42c3e96cb..a7a537b50595 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1701,10 +1701,8 @@ static void fib6_dump_end(struct netlink_callback *cb)
                 fib6_walker_unlink(w);
                 kfree(w);
         }
-        if (cb->args[1]) {
-                cb->done = (void*)cb->args[1];
-                cb->args[1] = 0;
-        }
+        cb->done = (void*)cb->args[1];
+        cb->args[1] = 0;
 }
 
 static int fib6_dump_done(struct netlink_callback *cb)