[NETLINK]: Fix infinite loops in synchronous netlink changes.

The qlen should continue to decrement, even if we
pop partially processed SKBs back onto the receive queue.

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 7 insertions, 9 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 6e1ab1e34b2e..75b6d33b5292 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -626,14 +626,13 @@ static void rtnetlink_rcv(struct sock *sk, int len)
                 if (qlen > skb_queue_len(&sk->sk_receive_queue))
                         qlen = skb_queue_len(&sk->sk_receive_queue);
 
-                while (qlen--) {
+                for (; qlen; qlen--) {
                         skb = skb_dequeue(&sk->sk_receive_queue);
                         if (rtnetlink_rcv_skb(skb)) {
-                                if (skb->len) {
+                                if (skb->len)
                                         skb_queue_head(&sk->sk_receive_queue,
                                                        skb);
-                                        qlen++;
-                                } else
+                                else
                                         kfree_skb(skb);
                                 break;
                         }
diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c
index 101ddef9ba9a..284a9998e53d 100644
--- a/net/decnet/netfilter/dn_rtmsg.c
+++ b/net/decnet/netfilter/dn_rtmsg.c
@@ -121,7 +121,7 @@ static void dnrmg_receive_user_sk(struct sock *sk, int len)
         struct sk_buff *skb;
         unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
 
-        while (qlen-- && (skb = skb_dequeue(&sk->sk_receive_queue))) {
+        for (; qlen && (skb = skb_dequeue(&sk->sk_receive_queue)); qlen--) {
                 dnrmg_receive_user_skb(skb);
                 kfree_skb(skb);
         }
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index dab112f1dd8a..e8740a4a1d78 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1018,14 +1018,13 @@ static void xfrm_netlink_rcv(struct sock *sk, int len)
                 if (qlen > skb_queue_len(&sk->sk_receive_queue))
                         qlen = skb_queue_len(&sk->sk_receive_queue);
 
-                while (qlen--) {
+                for (; qlen; qlen--) {
                         skb = skb_dequeue(&sk->sk_receive_queue);
                         if (xfrm_user_rcv_skb(skb)) {
-                                if (skb->len) {
+                                if (skb->len)
                                         skb_queue_head(&sk->sk_receive_queue,
                                                        skb);
-                                        qlen++;
-                                } else
+                                else
                                         kfree_skb(skb);
                                 break;
                         }