lwtunnel: Validate RTA_ENCAP_TYPE attribute length

lwtunnel_valid_encap_type_attr is used to validate encap attributes
within a multipath route. Add length validation checking to the type.

lwtunnel_valid_encap_type_attr is called converting attributes to
fib{6,}_config struct which means it is used before fib_get_nhs,
ip6_route_multipath_add, and ip6_route_multipath_del - other
locations that use rtnh_ok and then nla_get_u16 on RTA_ENCAP_TYPE
attribute.

Fixes: 9ed59592e3 ("lwtunnel: fix autoload of lwt modules")

Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern 2021-12-30 17:36:35 -07:00 committed by David S. Miller
parent 1ff15a710a
commit 8bda81a4d4
3 changed files with 11 additions and 0 deletions

View File

@ -197,6 +197,10 @@ int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining,
nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
if (nla_entype) {
if (nla_len(nla_entype) < sizeof(u16)) {
NL_SET_ERR_MSG(extack, "Invalid RTA_ENCAP_TYPE");
return -EINVAL;
}
encap_type = nla_get_u16(nla_entype);
if (lwtunnel_valid_encap_type(encap_type,

View File

@ -740,6 +740,9 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
}
fib_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
/* RTA_ENCAP_TYPE length checked in
* lwtunnel_valid_encap_type_attr
*/
nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
if (nla)
fib_cfg.fc_encap_type = nla_get_u16(nla);

View File

@ -5287,6 +5287,10 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
r_cfg.fc_flags |= RTF_GATEWAY;
}
r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
/* RTA_ENCAP_TYPE length checked in
* lwtunnel_valid_encap_type_attr
*/
nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
if (nla)
r_cfg.fc_encap_type = nla_get_u16(nla);