[PATCH 4.9 271/310] rxrpc: check return value of skb_to_sgvec always

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

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

commit 89a5ea99662505d2d61f2a3030a6896c2cb3cdb0 upstream.

Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com>
Acked-by: David Howells <dhowe...@redhat.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Nathan Chancellor <natechancel...@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gre...@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];