releases/4.9.94/ipsec-check-return-value-of-skb_to_sgvec-always.patch

From 3f29770723fe498a5c5f57c3a31a996ebdde03e1 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sun, 4 Jun 2017 04:16:23 +0200
Subject: ipsec: check return value of skb_to_sgvec always

From: Jason A. Donenfeld <Jason@zx2c4.com>

commit 3f29770723fe498a5c5f57c3a31a996ebdde03e1 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 fca11ebde3f0]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/ipv4/ah4.c  |    8 ++++++--
 net/ipv4/esp4.c |   13 ++++++++-----
 net/ipv6/ah6.c  |    8 ++++++--
 net/ipv6/esp6.c |   12 ++++++++----
 4 files changed, 28 insertions(+), 13 deletions(-)

--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -220,7 +220,9 @@ static int ah_output(struct xfrm_state *
 	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
 	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 */
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -268,10 +268,11 @@ static int esp_output(struct xfrm_state
 	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 *
 	}
 
 	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);
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -423,7 +423,9 @@ static int ah6_output(struct xfrm_state
 	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 *
 	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 */
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -248,9 +248,11 @@ static int esp6_output(struct xfrm_state
 	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
 	}
 
 	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);