Re: [PATCH v8 3/5] rxrpc: check return value of skb_to_sgvec always

[Jason A. Donenfeld]

On Mon, May 15, 2017 at 3:11 PM, David Howells  wrote:
> skb_to_sgvec() can return -EMSGSIZE in some circumstances.  You shouldn't
> return -ENOMEM here in such a case.

Noted. I'll fix this up for the next round.

Re: [PATCH v8 3/5] rxrpc: check return value of skb_to_sgvec always

[David Howells]

Jason A. Donenfeld  wrote:

> + if (unlikely(skb_to_sgvec(skb, sg, offset, 8) < 0))
> + goto nomem;
> ...
> + if (unlikely(skb_to_sgvec(skb, sg, offset, len) < 0)) {
> + if (sg != _sg)
> + kfree(sg);
> + goto nomem;

skb_to_sgvec() can return -EMSGSIZE in some circumstances.  You shouldn't
return -ENOMEM here in such a case.

David

[PATCH v8 3/5] rxrpc: check return value of skb_to_sgvec always

[Jason A. Donenfeld]

Signed-off-by: Jason A. Donenfeld 
Cc: David Howells 
---
 net/rxrpc/rxkad.c | 13 ++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 1bb9b2ccc267..ecab9334e3c1 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -227,7 +227,9 @@ static int rxkad_secure_packet_encrypt(const struct 
rxrpc_call *call,
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);
 
@@ -342,7 +344,8 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, 
struct sk_buff *skb,
goto nomem;
 
sg_init_table(sg, nsg);
-   skb_to_sgvec(skb, sg, offset, 8);
+   if (unlikely(skb_to_sgvec(skb, sg, offset, 8) < 0))
+   goto nomem;
 
/* start the decryption afresh */
memset(, 0, sizeof(iv));
@@ -434,7 +437,11 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, 
struct sk_buff *skb,
}
 
sg_init_table(sg, nsg);
-   skb_to_sgvec(skb, sg, offset, len);
+   if (unlikely(skb_to_sgvec(skb, sg, offset, len) < 0)) {
+   if (sg != _sg)
+   kfree(sg);
+   goto nomem;
+   }
 
/* decrypt from the session key */
token = call->conn->params.key->payload.data[0];
-- 
2.13.0