netfilter: nf_conntrack_h323: lost .data_len definition for Q.931/ipv6

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.

Fixes: 1afc56794e03 ("netfilter: nf_ct_helper: implement variable length helper private data") # v3.5
cc: stable@vger.kernel.org
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index f65d93639d12595884081726808f4c1e17caec03..29fe1e7eac889bb33f5539ca2c44a28659ac4083 100644 (file)
--- 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,