l2tp: double-check l2specific_type provided by userspace

Add sanity check on l2specific_type provided by userspace in
l2tp_nl_cmd_session_create() since just L2TP_L2SPECTYPE_DEFAULT and
L2TP_L2SPECTYPE_NONE are currently supported.
Moreover explicitly set l2specific_type to L2TP_L2SPECTYPE_DEFAULT
only if the userspace does not provide a value for it

Reviewed-by: Guillaume Nault <g.nault@alphalink.fr>
Tested-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lorenzo Bianconi 2018-01-16 23:01:54 +01:00 committed by David S. Miller
parent e0e8a14971
commit dfffc97d0e

View File

@ -550,9 +550,16 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
if (info->attrs[L2TP_ATTR_DATA_SEQ])
cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]);
cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
if (info->attrs[L2TP_ATTR_L2SPEC_TYPE])
if (info->attrs[L2TP_ATTR_L2SPEC_TYPE]) {
cfg.l2specific_type = nla_get_u8(info->attrs[L2TP_ATTR_L2SPEC_TYPE]);
if (cfg.l2specific_type != L2TP_L2SPECTYPE_DEFAULT &&
cfg.l2specific_type != L2TP_L2SPECTYPE_NONE) {
ret = -EINVAL;
goto out_tunnel;
}
} else {
cfg.l2specific_type = L2TP_L2SPECTYPE_DEFAULT;
}
cfg.l2specific_len = 4;
if (info->attrs[L2TP_ATTR_L2SPEC_LEN])