[PATCH] crypto: chtls - use after free in chtls_pt_recvmsg()

[Dan Carpenter]

We call chtls_free_skb() but then we dereference it on the next lines.
Also "skb" can't be NULL, we just dereferenced it on the line before.

I have moved the free down a couple lines to fix this issue.

Fixes: 17a7d24aa89d ("crypto: chtls - generic handling of data and hdr")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

diff --git a/drivers/crypto/chelsio/chtls/chtls_io.c b/drivers/crypto/chelsio/chtls/chtls_io.c
index 51fc6821cbbf..708e232e3cdf 100644
--- a/drivers/crypto/chelsio/chtls/chtls_io.c
+++ b/drivers/crypto/chelsio/chtls/chtls_io.c
@@ -1548,15 +1548,14 @@ static int chtls_pt_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 			tp->urg_data = 0;
 
 		if ((avail + offset) >= skb->len) {
-			if (likely(skb))
-				chtls_free_skb(sk, skb);
-			buffers_freed++;
 			if (ULP_SKB_CB(skb)->flags & ULPCB_FLAG_TLS_HDR) {
 				tp->copied_seq += skb->len;
 				hws->rcvpld = skb->hdr_len;
 			} else {
 				tp->copied_seq += hws->rcvpld;
 			}
+			chtls_free_skb(sk, skb);
+			buffers_freed++;
 			hws->copied_seq = 0;
 			if (copied >= target &&
 			    !skb_peek(&sk->sk_receive_queue))