From: Vasily Averin <vvs@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx Reviewed-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/netfilter/nf_conntrack_h323_main.c | 1 + 1 file changed, 1 insertion(+) --- 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_con { .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,