Re: [PATCH 2/3] netlink: nal_parse_nested_compat was not parsing nested attributes

[David Miller <davem@davemloft.net>]

From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Date: Thu, 21 Aug 2008 17:51:26 -0700

Please at least CC: the author of the patch you are reverting so
that they can provide feedback and have a look at this.

Thomas Graf CC:'d.

> From: Alexander Duyck <alexander.h.duyck@intel.com>
> 
> This patch reverts previous commit: b9a2f2e450b0f770bb4347ae8d48eb2dea701e24
> netlink: Fix nla_parse_nested_compat() to call nla_parse() directly
> 
> The purpose of nla_parse_nested_compat is to parse attributes which contain a
> struct followed by a container attribute with a stream of nested attributes.
> This patch reverts the previous patch which assumed that there was no container
> attribute due to a malformed string of attributes being generated by
> netem_parse_opts
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> ---
> 
>  include/net/netlink.h |   11 +++++------
>  1 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/include/net/netlink.h b/include/net/netlink.h
> index 18024b8..b295cd1 100644
> --- a/include/net/netlink.h
> +++ b/include/net/netlink.h
> @@ -770,13 +770,12 @@ static inline int __nla_parse_nested_compat(struct nlattr *tb[], int maxtype,
>  					    const struct nla_policy *policy,
>  					    int len)
>  {
> -	int nested_len = nla_len(nla) - NLA_ALIGN(len);
> -
> -	if (nested_len < 0)
> +	if (nla_len(nla) < len)
>  		return -EINVAL;
> -	if (nested_len >= nla_attr_size(0))
> -		return nla_parse(tb, maxtype, nla_data(nla) + NLA_ALIGN(len),
> -				 nested_len, policy);
> +	if (nla_len(nla) >= NLA_ALIGN(len) + sizeof(struct nlattr))
> +		return nla_parse_nested(tb, maxtype,
> +					nla_data(nla) + NLA_ALIGN(len),
> +					policy);
>  	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
>  	return 0;
>  }
>