netrom: fix a memory leak in nr_rx_frame()

When the skb is associated with a new sock, just assigning
it to skb->sk is not sufficient, we have to set its destructor
to free the sock properly too.

Reported-by: syzbot+d6636a36d3c34bd88938@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index 86b87925ef34dde0d625c20731c1fc11b2651ceb..96740d389377170b90a5d3d2dba3482bd293eb9a 100644 (file)
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -869,7 +869,7 @@ int nr_rx_frame(struct sk_buff *skb, struct net_device *dev)
        unsigned short frametype, flags, window, timeout;
        int ret;
 
-       skb->sk = NULL;         /* Initially we don't know who it's for */
+       skb_orphan(skb);
 
        /*
         *      skb->data points to the netrom frame start
@@ -968,6 +968,7 @@ int nr_rx_frame(struct sk_buff *skb, struct net_device *dev)
        window = skb->data[20];
 
        skb->sk             = make;
+       skb->destructor     = sock_efree;
        make->sk_state      = TCP_ESTABLISHED;
 
        /* Fill in his circuit details */