Re: [PATCH v6 3/5] rxrpc: check return value of skb_to_sgvec always

[Sabrina Dubroca]

2017-04-25, 20:47:32 +0200, Jason A. Donenfeld wrote:
> Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com>
> ---
>  net/rxrpc/rxkad.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
> index 4374e7b9c7bf..dcf46c9c3ece 100644
> --- a/net/rxrpc/rxkad.c
> +++ b/net/rxrpc/rxkad.c
[...]
> @@ -429,7 +432,8 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, 
> struct sk_buff *skb,
>       }
>  

Adding a few more lines of context:

        sg = _sg;
        if (unlikely(nsg > 4)) {
                sg = kmalloc(sizeof(*sg) * nsg, GFP_NOIO);
                if (!sg)
                        goto nomem;
        }

>       sg_init_table(sg, nsg);
> -     skb_to_sgvec(skb, sg, offset, len);
> +     if (unlikely(skb_to_sgvec(skb, sg, offset, len) < 0))
> +             goto nomem;

You're leaking sg when nsg > 4, you'll need to add this:

        if (sg != _sg)
                kfree(sg);



BTW, when you resubmit, please Cc: the maintainers of the files you're
changing for each patch, so that they can review this stuff. And send
patch 1 to all of them, otherwise they might be surprised that we even
need <0 checking after calls to skb_to_sgvec.

You might also want to add a cover letter.

-- 
Sabrina