ipsec: check return value of skb_to_sgvec always

BugLink: http://bugs.launchpad.net/bugs/1765010

commit 3f297707 upstream.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[natechancellor: Adjusted context due to lack of fca11ebd]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

net/ipv4/ah4.c

@@ -220,7 +220,9 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
 	ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
 
 	sg_init_table(sg, nfrags + sglists);
-	skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+	err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+	if (unlikely(err < 0))
+		goto out_free;
 
 	if (x->props.flags & XFRM_STATE_ESN) {
 		/* Attach seqhi sg right after packet payload */
@@ -393,7 +395,9 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 	skb_push(skb, ihl);
 
 	sg_init_table(sg, nfrags + sglists);
-	skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+	err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+	if (unlikely(err < 0))
+		goto out_free;
 
 	if (x->props.flags & XFRM_STATE_ESN) {
 		/* Attach seqhi sg right after packet payload */

net/ipv4/esp4.c

@@ -268,10 +268,11 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
 	esph->spi = x->id.spi;
 
 	sg_init_table(sg, nfrags);
-	skb_to_sgvec(skb, sg,
-		     (unsigned char *)esph - skb->data,
-		     assoclen + ivlen + clen + alen);
-
+	err = skb_to_sgvec(skb, sg,
+		           (unsigned char *)esph - skb->data,
+		           assoclen + ivlen + clen + alen);
+	if (unlikely(err < 0))
+		goto error;
 	aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
 	aead_request_set_ad(req, assoclen);
 
@@ -481,7 +482,9 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 	}
 
 	sg_init_table(sg, nfrags);
-	skb_to_sgvec(skb, sg, 0, skb->len);
+	err = skb_to_sgvec(skb, sg, 0, skb->len);
+	if (unlikely(err < 0))
+		goto out;
 
 	aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
 	aead_request_set_ad(req, assoclen);

net/ipv6/ah6.c

@@ -423,7 +423,9 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
 	ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
 
 	sg_init_table(sg, nfrags + sglists);
-	skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+	err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+	if (unlikely(err < 0))
+		goto out_free;
 
 	if (x->props.flags & XFRM_STATE_ESN) {
 		/* Attach seqhi sg right after packet payload */
@@ -603,7 +605,9 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
 	ip6h->hop_limit   = 0;
 
 	sg_init_table(sg, nfrags + sglists);
-	skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+	err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+	if (unlikely(err < 0))
+		goto out_free;
 
 	if (x->props.flags & XFRM_STATE_ESN) {
 		/* Attach seqhi sg right after packet payload */

net/ipv6/esp6.c

@@ -248,9 +248,11 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 	esph->spi = x->id.spi;
 
 	sg_init_table(sg, nfrags);
-	skb_to_sgvec(skb, sg,
-		     (unsigned char *)esph - skb->data,
-		     assoclen + ivlen + clen + alen);
+	err = skb_to_sgvec(skb, sg,
+		           (unsigned char *)esph - skb->data,
+		           assoclen + ivlen + clen + alen);
+	if (unlikely(err < 0))
+		goto error;
 
 	aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
 	aead_request_set_ad(req, assoclen);
@@ -423,7 +425,9 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
 	}
 
 	sg_init_table(sg, nfrags);
-	skb_to_sgvec(skb, sg, 0, skb->len);
+	ret = skb_to_sgvec(skb, sg, 0, skb->len);
+	if (unlikely(ret < 0))
+		goto out;
 
 	aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
 	aead_request_set_ad(req, assoclen);