sctp: avoid running the sctp state machine recursively

[mirror_ubuntu-disco-kernel.git] / net / tls / tls_device_fallback.c

diff --git a/net/tls/tls_device_fallback.c b/net/tls/tls_device_fallback.c
index 450a6dbc5a888421c36f71f85c31365d6138562b..426dd97725e4a1235eca9cf65cec9eadecf10359 100644 (file)
--- a/net/tls/tls_device_fallback.c
+++ b/net/tls/tls_device_fallback.c
@@ -193,18 +193,26 @@ static void update_chksum(struct sk_buff *skb, int headln)
 
 static void complete_skb(struct sk_buff *nskb, struct sk_buff *skb, int headln)
 {
+       struct sock *sk = skb->sk;
+       int delta;
+
        skb_copy_header(nskb, skb);
 
        skb_put(nskb, skb->len);
        memcpy(nskb->data, skb->data, headln);
-       update_chksum(nskb, headln);
 
        nskb->destructor = skb->destructor;
-       nskb->sk = skb->sk;
+       nskb->sk = sk;
        skb->destructor = NULL;
        skb->sk = NULL;
-       refcount_add(nskb->truesize - skb->truesize,
-                    &nskb->sk->sk_wmem_alloc);
+
+       update_chksum(nskb, headln);
+
+       delta = nskb->truesize - skb->truesize;
+       if (likely(delta < 0))
+               WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc));
+       else if (delta)
+               refcount_add(delta, &sk->sk_wmem_alloc);
 }
 
 /* This function may be called after the user socket is already