rose: fix dev_put() leak in rose_loopback_timer()

commit ff91adc54db2b62c7cdf063ff761eceb5adf2215 upstream.

rose_rx_call_request() always consumes or returns the skb but never
releases the device reference obtained from rose_dev_get().  When
rose_rx_call_request() succeeds (returns non-zero) dev_put() was never
called, leaking one reference per loopback CALL_REQUEST.

Move dev_put() outside the conditional so it is called unconditionally
after rose_rx_call_request() in all cases.

Also remove the dead check (!rose_loopback_neigh->dev &&
!rose_loopback_neigh->loopback) that immediately precedes it: the
loopback neighbour always has loopback=1 so this condition can never
be true.

Fixes: 0453c68 ("net/rose: fix unbound loop in rose_loopback_timer()")
Signed-off-by: Bernard Pidoux <bernard.f6bvp@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: f6bvp

net/rose/rose_loopback.c

@@ -96,22 +96,15 @@ static void rose_loopback_timer(struct timer_list *unused)
 		}
 
 		if (frametype == ROSE_CALL_REQUEST) {
-			if (!rose_loopback_neigh->dev &&
-			    !rose_loopback_neigh->loopback) {
-				kfree_skb(skb);
-				continue;
-			}
-
 			dev = rose_dev_get(dest);
 			if (!dev) {
 				kfree_skb(skb);
 				continue;
 			}
 
-			if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) {
-				dev_put(dev);
+			if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0)
 				kfree_skb(skb);
-			}
+			dev_put(dev);
 		} else {
 			kfree_skb(skb);
 		}