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

From 89a5ea99662505d2d61f2a3030a6896c2cb3cdb0 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sun, 4 Jun 2017 04:16:24 +0200
Subject: rxrpc: check return value of skb_to_sgvec always

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

commit 89a5ea99662505d2d61f2a3030a6896c2cb3cdb0 upstream.

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

---
 net/rxrpc/rxkad.c |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -229,7 +229,9 @@ static int rxkad_secure_packet_encrypt(c
 	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);
 
@@ -325,7 +327,7 @@ static int rxkad_verify_packet_1(struct
 	struct sk_buff *trailer;
 	u32 data_size, buf;
 	u16 check;
-	int nsg;
+	int nsg, ret;
 
 	_enter("");
 
@@ -342,7 +344,9 @@ static int rxkad_verify_packet_1(struct
 		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));
@@ -405,7 +409,7 @@ static int rxkad_verify_packet_2(struct
 	struct sk_buff *trailer;
 	u32 data_size, buf;
 	u16 check;
-	int nsg;
+	int nsg, ret;
 
 	_enter(",{%d}", skb->len);
 
@@ -429,7 +433,12 @@ static int rxkad_verify_packet_2(struct
 	}
 
 	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];