From 76936ddb4913a39a9a380e191493aec145c6bc7f Mon Sep 17 00:00:00 2001 From: David Ahern Date: Thu, 30 Dec 2021 17:36:35 -0700 Subject: [PATCH] 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: 9ed59592e3e3 ("lwtunnel: fix autoload of lwt modules") Signed-off-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/lwtunnel.c | 4 ++++ net/ipv4/fib_semantics.c | 3 +++ net/ipv6/route.c | 4 ++++ 3 files changed, 11 insertions(+) diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index 2f9c0de533c7..0b64f015b3b0 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -190,6 +190,10 @@ 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, diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index c462778cbcce..ce4b28f01148 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -732,6 +732,9 @@ 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); diff --git a/net/ipv6/route.c b/net/ipv6/route.c index e34cb4db6eb1..53861f9c8ce0 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5156,6 +5156,10 @@ 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);