From: David Ahern dsahern@kernel.org
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: 9ed59592e3e3 ("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 --- net/core/lwtunnel.c | 4 ++++ net/ipv4/fib_semantics.c | 3 +++ net/ipv6/route.c | 4 ++++ 3 files changed, 11 insertions(+)
--- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -197,6 +197,10 @@ int lwtunnel_valid_encap_type_attr(struc 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, --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -740,6 +740,9 @@ static int fib_get_nhs(struct fib_info * }
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); --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5287,6 +5287,10 @@ static int ip6_route_multipath_add(struc 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);