Re: [PATCH v4.10] netfilter: nf_conntrack_h323: lost .data_len definition for Q.931/ipv6

[Pablo Neira Ayuso <pablo@netfilter.org>]

CC'ing stable@vger.kernel.org

On Tue, Jun 09, 2020 at 10:53:22AM +0300, Vasily Averin wrote:
> Could you please push this patch into stable@?
> it fixes memory corruption in kernels  v3.5 .. v4.10
> 
> Lost .data_len definition leads to write beyond end of
> struct nf_ct_h323_master. Usually it corrupts following
> struct nf_conn_nat, however if nat is not loaded it corrupts
> following slab object.
> 
> In mainline this problem went away in v4.11,
> after commit 9f0f3ebeda47 ("netfilter: helpers: remove data_len usage
> for inkernel helpers") however many stable kernels are still affected.

-stable maintainers of: 3.16, 4.4 and 4.9.

Please apply this patch, thanks.

> cc: stable@vger.kernel.org
> Fixes: 1afc56794e03 ("netfilter: nf_ct_helper: implement variable length helper private data") # v3.5
> Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
> ---
>  net/netfilter/nf_conntrack_h323_main.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
> index f65d93639d12..29fe1e7eac88 100644
> --- a/net/netfilter/nf_conntrack_h323_main.c
> +++ b/net/netfilter/nf_conntrack_h323_main.c
> @@ -1225,6 +1225,7 @@ static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
>  	{
>  		.name			= "Q.931",
>  		.me			= THIS_MODULE,
> +		.data_len		= sizeof(struct nf_ct_h323_master),
>  		.tuple.src.l3num	= AF_INET6,
>  		.tuple.src.u.tcp.port	= cpu_to_be16(Q931_PORT),
>  		.tuple.dst.protonum	= IPPROTO_TCP,
> -- 
> 2.17.1
>