[NETFILTER]: nfnetlink_{queue,log}: return proper error codes in instance_create

Currently we return EINVAL for "instance exists", "allocation failed" and
"module unloaded below us", which is completely inapproriate.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 23 insertions, 12 deletions

diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index c12e1d1bd00..ac58dc9d724 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -128,19 +128,23 @@ static struct nfulnl_instance *
 instance_create(u_int16_t group_num, int pid)
 {
         struct nfulnl_instance *inst;
+        int err;
 
         write_lock_bh(&instances_lock);
         if (__instance_lookup(group_num)) {
-                inst = NULL;
+                err = -EEXIST;
                 goto out_unlock;
         }
 
         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
-        if (!inst)
+        if (!inst) {
+                err = -ENOMEM;
                 goto out_unlock;
+        }
 
         if (!try_module_get(THIS_MODULE)) {
                 kfree(inst);
+                err = -EAGAIN;
                 goto out_unlock;
         }
 
@@ -169,7 +173,7 @@ instance_create(u_int16_t group_num, int pid)
 
 out_unlock:
         write_unlock_bh(&instances_lock);
-        return NULL;
+        return ERR_PTR(err);
 }
 
 static void __nfulnl_flush(struct nfulnl_instance *inst);
@@ -731,8 +735,8 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 
                         inst = instance_create(group_num,
                                                NETLINK_CB(skb).pid);
-                        if (!inst) {
-                                ret = -EINVAL;
+                        if (IS_ERR(inst)) {
+                                ret = PTR_ERR(inst);
                                 goto out;
                         }
                         break;
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 370f0af50f4..51476f82bb5 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -89,16 +89,21 @@ instance_lookup(u_int16_t queue_num)
 static struct nfqnl_instance *
 instance_create(u_int16_t queue_num, int pid)
 {
-        struct nfqnl_instance *inst = NULL;
+        struct nfqnl_instance *inst;
         unsigned int h;
+        int err;
 
         spin_lock(&instances_lock);
-        if (instance_lookup(queue_num))
+        if (instance_lookup(queue_num)) {
+                err = -EEXIST;
                 goto out_unlock;
+        }
 
         inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
-        if (!inst)
+        if (!inst) {
+                err = -ENOMEM;
                 goto out_unlock;
+        }
 
         inst->queue_num = queue_num;
         inst->peer_pid = pid;
@@ -109,8 +114,10 @@ instance_create(u_int16_t queue_num, int pid)
         INIT_LIST_HEAD(&inst->queue_list);
         INIT_RCU_HEAD(&inst->rcu);
 
-        if (!try_module_get(THIS_MODULE))
+        if (!try_module_get(THIS_MODULE)) {
+                err = -EAGAIN;
                 goto out_free;
+        }
 
         h = instance_hashfn(queue_num);
         hlist_add_head_rcu(&inst->hlist, &instance_table[h]);
@@ -123,7 +130,7 @@ out_free:
         kfree(inst);
 out_unlock:
         spin_unlock(&instances_lock);
-        return NULL;
+        return ERR_PTR(err);
 }
 
 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
@@ -724,8 +731,8 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
                                 goto err_out_unlock;
                         }
                         queue = instance_create(queue_num, NETLINK_CB(skb).pid);
-                        if (!queue) {
-                                ret = -EINVAL;
+                        if (IS_ERR(queue)) {
+                                ret = PTR_ERR(queue);
                                 goto err_out_unlock;
                         }
                         break;