[IPV6] TCPMD5: Fix deleting key operation.

Due to the bug, refcnt for md5sig pool was leaked when
an user try to delete a key if we have more than one key.
In addition to the leakage, we returned incorrect return
result value for userspace.

This fix should close Bug #9418, reported by <ming-baini@163.com>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 4 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index b1bfbdd85d3c..93980c3b83e6 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -637,10 +637,6 @@ static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
                                 kfree(tp->md5sig_info->keys6);
                                 tp->md5sig_info->keys6 = NULL;
                                 tp->md5sig_info->alloced6 = 0;
-
-                                tcp_free_md5sig_pool();
-
-                                return 0;
                         } else {
                                 /* shrink the database */
                                 if (tp->md5sig_info->entries6 != i)
@@ -649,6 +645,8 @@ static int tcp_v6_md5_do_del(struct sock *sk, struct in6_addr *peer)
                                                 (tp->md5sig_info->entries6 - i)
                                                 * sizeof (tp->md5sig_info->keys6[0]));
                         }
+                        tcp_free_md5sig_pool();
+                        return 0;
                 }
         }
         return -ENOENT;