Re: [patch] netfilter: potential NULL dereference in get_inner_hdr()

[Hans Schillstrom <hans.schillstrom@ericsson.com>]

On Saturday 12 May 2012 13:00:03 Dan Carpenter wrote:
> There is a typo in the error checking and "&&" was used instead of "||".
> If skb_header_pointer() returns NULL then it leads to a NULL
> dereference.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Ack-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
 
> ---
> Btw, this is new code and Sparse complains about endian bugs.

Can you give me some hints here, arch , compiler version etc.
I guess it was input to hmark_addr_mask() that complains ?

> 
> diff --git a/net/netfilter/xt_HMARK.c b/net/netfilter/xt_HMARK.c
> index 32fbd73..5817d03 100644
> --- a/net/netfilter/xt_HMARK.c
> +++ b/net/netfilter/xt_HMARK.c
> @@ -223,7 +223,7 @@ static int get_inner_hdr(const struct sk_buff *skb, int iphsz, int *nhoff)
>  
>  	/* Not enough header? */
>  	icmph = skb_header_pointer(skb, *nhoff + iphsz, sizeof(_ih), &_ih);
> -	if (icmph = NULL && icmph->type > NR_ICMP_TYPES)
> +	if (icmph = NULL || icmph->type > NR_ICMP_TYPES)
>  		return 0;
>  
>  	/* Error message? */
> --
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-- 
Regards
Hans Schillstrom <hans.schillstrom@ericsson.com>