[NETFILTER]: nfnetlink_queue: fix checks in nfqnl_recv_config

The peer_pid must be checked in all cases when a queue exists, currently
it is not checked if for NFQA_CFG_QUEUE_MAXLEN when a NFQA_CFG_CMD
attribute exists in some cases. Same for the queue existance check,
which can cause a NULL pointer dereference.

Also consistently return -ENODEV for "queue not found". -ENOENT would
be better, but that is already used to indicate a queued skb id doesn't
exist.

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

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index bd18de7..4abf62a 100644 (file)
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -781,8 +781,14 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
        QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
 
        queue = instance_lookup_get(queue_num);
+       if (queue && queue->peer_pid != NETLINK_CB(skb).pid) {
+               ret = -EPERM;
+               goto out_put;
+       }
+
        if (nfqa[NFQA_CFG_CMD]) {
                struct nfqnl_msg_config_cmd *cmd;
+
                cmd = nla_data(nfqa[NFQA_CFG_CMD]);
                QDEBUG("found CFG_CMD\n");
 
@@ -798,12 +804,6 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
                case NFQNL_CFG_CMD_UNBIND:
                        if (!queue)
                                return -ENODEV;
-
-                       if (queue->peer_pid != NETLINK_CB(skb).pid) {
-                               ret = -EPERM;
-                               goto out_put;
-                       }
-
                        instance_destroy(queue);
                        break;
                case NFQNL_CFG_CMD_PF_BIND:
@@ -820,25 +820,13 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
                        ret = -EINVAL;
                        break;
                }
-       } else {
-               if (!queue) {
-                       QDEBUG("no config command, and no instance ENOENT\n");
-                       ret = -ENOENT;
-                       goto out_put;
-               }
-
-               if (queue->peer_pid != NETLINK_CB(skb).pid) {
-                       QDEBUG("no config command, and wrong pid\n");
-                       ret = -EPERM;
-                       goto out_put;
-               }
        }
 
        if (nfqa[NFQA_CFG_PARAMS]) {
                struct nfqnl_msg_config_params *params;
 
                if (!queue) {
-                       ret = -ENOENT;
+                       ret = -ENODEV;
                        goto out_put;
                }
                params = nla_data(nfqa[NFQA_CFG_PARAMS]);
@@ -848,6 +836,11 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 
        if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
                __be32 *queue_maxlen;
+
+               if (!queue) {
+                       ret = -ENODEV;
+                       goto out_put;
+               }
                queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
                spin_lock_bh(&queue->lock);
                queue->queue_maxlen = ntohl(*queue_maxlen);