Re: [PATCH] Phonet: Correct header retrieval after pskb_may_pull

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mardi 28 septembre 2010 à 14:40 +0530, Kumar A Sanghvi a écrit :
> From: Kumar Sanghvi <kumar.sanghvi@stericsson.com>
> 
> Retrieve the header after doing pskb_may_pull since, pskb_may_pull
> could change the buffer structure.
> 
> This is based on the comment given by Eric Dumazet on Phonet
> Pipe controller patch for a similar problem.
> 
> Signed-off-by: Kumar Sanghvi <kumar.sanghvi@stericsson.com>
> Acked-by: Linus Walleij <linus.walleij@stericsson.com>
> ---
>  net/phonet/pep.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/net/phonet/pep.c b/net/phonet/pep.c
> index 7bf23cf..9746c6d 100644
> --- a/net/phonet/pep.c
> +++ b/net/phonet/pep.c
> @@ -507,12 +507,13 @@ static void pipe_grant_credits(struct sock *sk)
>  static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
>  {
>  	struct pep_sock *pn = pep_sk(sk);
> -	struct pnpipehdr *hdr = pnp_hdr(skb);
> +	struct pnpipehdr *hdr;
>  	int wake = 0;
>  
>  	if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
>  		return -EINVAL;
>  
> +	hdr = pnp_hdr(skb);
>  	if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
>  		LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
>  				(unsigned)hdr->data[0]);

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>