lwtunnel: Validate RTA_ENCAP_TYPE attribute length

commit 8bda81a4d400cf8a72e554012f0d8c45e07a3904 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Ahern
2021-12-30 17:36:35 -07:00
committed by Greg Kroah-Hartman
parent 48d5adb08d
commit f403b5f96e
3 changed files with 11 additions and 0 deletions

View File

@@ -741,6 +741,9 @@ 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);