tcp: properly handle md5sig_pool references
Yan, Zheng [Thu, 29 Sep 2011 17:10:10 +0000 (17:10 +0000)]
tcp_v4_clear_md5_list() assumes that multiple tcp md5sig peers
only hold one reference to md5sig_pool. but tcp_v4_md5_do_add()
increases use count of md5sig_pool for each peer. This patch
makes tcp_v4_md5_do_add() only increases use count for the first
tcp md5sig peer.

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_ipv4.c
net/ipv6/tcp_ipv6.c

index c34f015..7963e03 100644 (file)
@@ -927,18 +927,21 @@ int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
                        }
                        sk_nocaps_add(sk, NETIF_F_GSO_MASK);
                }
-               if (tcp_alloc_md5sig_pool(sk) == NULL) {
+
+               md5sig = tp->md5sig_info;
+               if (md5sig->entries4 == 0 &&
+                   tcp_alloc_md5sig_pool(sk) == NULL) {
                        kfree(newkey);
                        return -ENOMEM;
                }
-               md5sig = tp->md5sig_info;
 
                if (md5sig->alloced4 == md5sig->entries4) {
                        keys = kmalloc((sizeof(*keys) *
                                        (md5sig->entries4 + 1)), GFP_ATOMIC);
                        if (!keys) {
                                kfree(newkey);
-                               tcp_free_md5sig_pool();
+                               if (md5sig->entries4 == 0)
+                                       tcp_free_md5sig_pool();
                                return -ENOMEM;
                        }
 
@@ -982,6 +985,7 @@ int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
                                kfree(tp->md5sig_info->keys4);
                                tp->md5sig_info->keys4 = NULL;
                                tp->md5sig_info->alloced4 = 0;
+                               tcp_free_md5sig_pool();
                        } else if (tp->md5sig_info->entries4 != i) {
                                /* Need to do some manipulation */
                                memmove(&tp->md5sig_info->keys4[i],
@@ -989,7 +993,6 @@ int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
                                        (tp->md5sig_info->entries4 - i) *
                                         sizeof(struct tcp4_md5sig_key));
                        }
-                       tcp_free_md5sig_pool();
                        return 0;
                }
        }
index 79cc646..7b8fc57 100644 (file)
@@ -591,7 +591,8 @@ static int tcp_v6_md5_do_add(struct sock *sk, const struct in6_addr *peer,
                        }
                        sk_nocaps_add(sk, NETIF_F_GSO_MASK);
                }
-               if (tcp_alloc_md5sig_pool(sk) == NULL) {
+               if (tp->md5sig_info->entries6 == 0 &&
+                       tcp_alloc_md5sig_pool(sk) == NULL) {
                        kfree(newkey);
                        return -ENOMEM;
                }
@@ -600,8 +601,9 @@ static int tcp_v6_md5_do_add(struct sock *sk, const struct in6_addr *peer,
                                       (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
 
                        if (!keys) {
-                               tcp_free_md5sig_pool();
                                kfree(newkey);
+                               if (tp->md5sig_info->entries6 == 0)
+                                       tcp_free_md5sig_pool();
                                return -ENOMEM;
                        }
 
@@ -647,6 +649,7 @@ static int tcp_v6_md5_do_del(struct sock *sk, const struct in6_addr *peer)
                                kfree(tp->md5sig_info->keys6);
                                tp->md5sig_info->keys6 = NULL;
                                tp->md5sig_info->alloced6 = 0;
+                               tcp_free_md5sig_pool();
                        } else {
                                /* shrink the database */
                                if (tp->md5sig_info->entries6 != i)
@@ -655,7 +658,6 @@ static int tcp_v6_md5_do_del(struct sock *sk, const struct in6_addr *peer)
                                                (tp->md5sig_info->entries6 - i)
                                                * sizeof (tp->md5sig_info->keys6[0]));
                        }
-                       tcp_free_md5sig_pool();
                        return 0;
                }
        }