rxrpc: check return value of skb_to_sgvec always

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rxrpc/rxkad.c

@@ -227,7 +227,9 @@ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
 	len &= ~(call->conn->size_align - 1);
 
 	sg_init_table(sg, nsg);
-	skb_to_sgvec(skb, sg, 0, len);
+	err = skb_to_sgvec(skb, sg, 0, len);
+	if (unlikely(err < 0))
+		goto out;
 	skcipher_request_set_crypt(req, sg, sg, len, iv.x);
 	crypto_skcipher_encrypt(req);
 
@@ -324,7 +326,7 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
 	bool aborted;
 	u32 data_size, buf;
 	u16 check;
-	int nsg;
+	int nsg, ret;
 
 	_enter("");
 
@@ -342,7 +344,9 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
 		goto nomem;
 
 	sg_init_table(sg, nsg);
-	skb_to_sgvec(skb, sg, offset, 8);
+	ret = skb_to_sgvec(skb, sg, offset, 8);
+	if (unlikely(ret < 0))
+		return ret;
 
 	/* start the decryption afresh */
 	memset(&iv, 0, sizeof(iv));
@@ -409,7 +413,7 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
 	bool aborted;
 	u32 data_size, buf;
 	u16 check;
-	int nsg;
+	int nsg, ret;
 
 	_enter(",{%d}", skb->len);
 
@@ -434,7 +438,12 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
 	}
 
 	sg_init_table(sg, nsg);
-	skb_to_sgvec(skb, sg, offset, len);
+	ret = skb_to_sgvec(skb, sg, offset, len);
+	if (unlikely(ret < 0)) {
+		if (sg != _sg)
+			kfree(sg);
+		return ret;
+	}
 
 	/* decrypt from the session key */
 	token = call->conn->params.key->payload.data[0];