Merge branch 'tls-warnings'

Jakub Kicinski says:

====================
net/tls: fix W=1 build warnings

This small series cleans up two outstanding W=1 build
warnings in tls code.  Both are set but not used variables.
The first case looks fairly straightforward.  In the second
I think it's better to propagate the error code, even if
not doing some does not lead to a crash with current code.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tls/tls_device.c

@@ -541,14 +541,11 @@ static int tls_device_push_pending_record(struct sock *sk, int flags)
 
 void tls_device_write_space(struct sock *sk, struct tls_context *ctx)
 {
-	int rc = 0;
-
 	if (!sk->sk_write_pending && tls_is_partially_sent_record(ctx)) {
 		gfp_t sk_allocation = sk->sk_allocation;
 
 		sk->sk_allocation = GFP_ATOMIC;
-		rc = tls_push_partial_record(sk, ctx,
-					     MSG_DONTWAIT | MSG_NOSIGNAL);
+		tls_push_partial_record(sk, ctx, MSG_DONTWAIT | MSG_NOSIGNAL);
 		sk->sk_allocation = sk_allocation;
 	}
 }

net/tls/tls_sw.c

@@ -119,23 +119,25 @@ static int skb_nsg(struct sk_buff *skb, int offset, int len)
 }
 
 static int padding_length(struct tls_sw_context_rx *ctx,
-			  struct tls_context *tls_ctx, struct sk_buff *skb)
+			  struct tls_prot_info *prot, struct sk_buff *skb)
 {
 	struct strp_msg *rxm = strp_msg(skb);
 	int sub = 0;
 
 	/* Determine zero-padding length */
-	if (tls_ctx->prot_info.version == TLS_1_3_VERSION) {
+	if (prot->version == TLS_1_3_VERSION) {
 		char content_type = 0;
 		int err;
 		int back = 17;
 
 		while (content_type == 0) {
-			if (back > rxm->full_len)
+			if (back > rxm->full_len - prot->prepend_size)
 				return -EBADMSG;
 			err = skb_copy_bits(skb,
 					    rxm->offset + rxm->full_len - back,
 					    &content_type, 1);
+			if (err)
+				return err;
 			if (content_type)
 				break;
 			sub++;
@@ -170,10 +172,18 @@ static void tls_decrypt_done(struct crypto_async_request *req, int err)
 		tls_err_abort(skb->sk, err);
 	} else {
 		struct strp_msg *rxm = strp_msg(skb);
-		rxm->full_len -= padding_length(ctx, tls_ctx, skb);
+		int pad;
+
+		pad = padding_length(ctx, prot, skb);
+		if (pad < 0) {
+			ctx->async_wait.err = pad;
+			tls_err_abort(skb->sk, pad);
+		} else {
+			rxm->full_len -= pad;
 			rxm->offset += prot->prepend_size;
 			rxm->full_len -= prot->overhead_size;
 		}
+	}
 
 	/* After using skb->sk to propagate sk through crypto async callback
 	 * we need to NULL it again.
@@ -1478,7 +1488,7 @@ static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
 	struct tls_prot_info *prot = &tls_ctx->prot_info;
 	int version = prot->version;
 	struct strp_msg *rxm = strp_msg(skb);
-	int err = 0;
+	int pad, err = 0;
 
 	if (!ctx->decrypted) {
 #ifdef CONFIG_TLS_DEVICE
@@ -1501,7 +1511,11 @@ static int decrypt_skb_update(struct sock *sk, struct sk_buff *skb,
 			*zc = false;
 		}
 
-		rxm->full_len -= padding_length(ctx, tls_ctx, skb);
+		pad = padding_length(ctx, prot, skb);
+		if (pad < 0)
+			return pad;
+
+		rxm->full_len -= pad;
 		rxm->offset += prot->prepend_size;
 		rxm->full_len -= prot->overhead_size;
 		tls_advance_record_sn(sk, &tls_ctx->rx, version);