From 0f651f98eadff91c0131576431ce20ded9d9c8af Mon Sep 17 00:00:00 2001
From: Sabrina Dubroca <sd@queasysnail.net>
Date: Wed, 4 Dec 2019 15:35:53 +0100
Subject: [PATCH 3/3] net: ipv6_stub: use ip6_dst_lookup_flow instead of
ip6_dst_lookup
[ Upstream commit 6c8991f41546c3c472503dff1ea9daaddf9331c2 ]
Fixes CVE-2020-1749
Backported from v5.5-rc1
Patch 3/3
ipv6_stub uses the ip6_dst_lookup function to allow other modules to
perform IPv6 lookups. However, this function skips the XFRM layer
entirely.
All users of ipv6_stub->ip6_dst_lookup use ip_route_output_flow (via the
ip_route_output_key and ip_route_output helpers) for their IPv4 lookups,
which calls xfrm_lookup_route(). This patch fixes this inconsistent
behavior by switching the stub to ip6_dst_lookup_flow, which also calls
xfrm_lookup_route().
This requires some changes in all the callers, as these two functions
take different arguments and have different return types.
Fixes: 5f81bd2e5d80 ("ipv6: export a stub for IPv6 symbols used by vxlan")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Carsten Schmid <carsten_schmid@mentor.com>
---
drivers/infiniband/core/addr.c | 7 +++----
drivers/infiniband/sw/rxe/rxe_net.c | 8 +++++---
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 11 +++++------
drivers/net/geneve.c | 4 +++-
drivers/net/vxlan.c | 8 +++-----
include/net/ipv6_stubs.h | 6 ++++--
net/ipv6/addrconf_core.c | 11 ++++++-----
net/ipv6/af_inet6.c | 2 +-
net/mpls/af_mpls.c | 7 +++----
net/tipc/udp_media.c | 9 ++++++---
10 files changed, 39 insertions(+), 34 deletions(-)
@@ -450,16 +450,15 @@ static int addr6_resolve(struct sockaddr_in6 *src_in,
struct flowi6 fl6;
struct dst_entry *dst;
struct rt6_info *rt;
- int ret;
memset(&fl6, 0, sizeof fl6);
fl6.daddr = dst_in->sin6_addr;
fl6.saddr = src_in->sin6_addr;
fl6.flowi6_oif = addr->bound_dev_if;
- ret = ipv6_stub->ipv6_dst_lookup(addr->net, NULL, &dst, &fl6);
- if (ret < 0)
- return ret;
+ dst = ipv6_stub->ipv6_dst_lookup_flow(addr->net, NULL, &fl6, NULL);
+ if (IS_ERR(dst))
+ return PTR_ERR(dst);
rt = (struct rt6_info *)dst;
if (ipv6_addr_any(&src_in->sin6_addr)) {
@@ -154,10 +154,12 @@ static struct dst_entry *rxe_find_route6(struct net_device *ndev,
memcpy(&fl6.daddr, daddr, sizeof(*daddr));
fl6.flowi6_proto = IPPROTO_UDP;
- if (unlikely(ipv6_stub->ipv6_dst_lookup(sock_net(recv_sockets.sk6->sk),
- recv_sockets.sk6->sk, &ndst, &fl6))) {
+ ndst = ipv6_stub->ipv6_dst_lookup_flow(sock_net(recv_sockets.sk6->sk),
+ recv_sockets.sk6->sk, &fl6,
+ NULL);
+ if (unlikely(IS_ERR(ndst))) {
pr_err_ratelimited("no route to %pI6\n", daddr);
- goto put;
+ return NULL;
}
if (unlikely(ndst->error)) {
@@ -1551,12 +1551,11 @@ static int mlx5e_route_lookup_ipv6(struct mlx5e_priv *priv,
#if IS_ENABLED(CONFIG_INET) && IS_ENABLED(CONFIG_IPV6)
struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
- int ret;
-
- ret = ipv6_stub->ipv6_dst_lookup(dev_net(mirred_dev), NULL, &dst,
- fl6);
- if (ret < 0)
- return ret;
+
+ dst = ipv6_stub->ipv6_dst_lookup_flow(dev_net(mirred_dev), NULL, fl6,
+ NULL);
+ if (IS_ERR(dst))
+ return PTR_ERR(dst);
*out_ttl = ip6_dst_hoplimit(dst);
@@ -797,7 +797,9 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb,
if (dst)
return dst;
}
- if (ipv6_stub->ipv6_dst_lookup(geneve->net, gs6->sock->sk, &dst, fl6)) {
+ dst = ipv6_stub->ipv6_dst_lookup_flow(geneve->net, gs6->sock->sk, fl6,
+ NULL);
+ if (IS_ERR(dst)) {
netdev_dbg(dev, "no route to %pI6\n", &fl6->daddr);
return ERR_PTR(-ENETUNREACH);
}
@@ -1963,7 +1963,6 @@ static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan,
bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
struct dst_entry *ndst;
struct flowi6 fl6;
- int err;
if (!sock6)
return ERR_PTR(-EIO);
@@ -1986,10 +1985,9 @@ static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan,
fl6.fl6_dport = dport;
fl6.fl6_sport = sport;
- err = ipv6_stub->ipv6_dst_lookup(vxlan->net,
- sock6->sock->sk,
- &ndst, &fl6);
- if (unlikely(err < 0)) {
+ ndst = ipv6_stub->ipv6_dst_lookup_flow(vxlan->net, sock6->sock->sk,
+ &fl6, NULL);
+ if (unlikely(IS_ERR(ndst))) {
netdev_dbg(dev, "no route to %pI6\n", daddr);
return ERR_PTR(-ENETUNREACH);
}
@@ -18,8 +18,10 @@ struct ipv6_stub {
const struct in6_addr *addr);
int (*ipv6_sock_mc_drop)(struct sock *sk, int ifindex,
const struct in6_addr *addr);
- int (*ipv6_dst_lookup)(struct net *net, struct sock *sk,
- struct dst_entry **dst, struct flowi6 *fl6);
+ struct dst_entry *(*ipv6_dst_lookup_flow)(struct net *net,
+ const struct sock *sk,
+ struct flowi6 *fl6,
+ const struct in6_addr *final_dst);
void (*udpv6_encap_enable)(void);
void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr,
const struct in6_addr *solicited_addr,
@@ -126,15 +126,16 @@ int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
}
EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
-static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
- struct dst_entry **u2,
- struct flowi6 *u3)
+static struct dst_entry *eafnosupport_ipv6_dst_lookup_flow(struct net *net,
+ const struct sock *sk,
+ struct flowi6 *fl6,
+ const struct in6_addr *final_dst)
{
- return -EAFNOSUPPORT;
+ return ERR_PTR(-EAFNOSUPPORT);
}
const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
- .ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup,
+ .ipv6_dst_lookup_flow = eafnosupport_ipv6_dst_lookup_flow,
};
EXPORT_SYMBOL_GPL(ipv6_stub);
@@ -875,7 +875,7 @@ static struct pernet_operations inet6_net_ops = {
static const struct ipv6_stub ipv6_stub_impl = {
.ipv6_sock_mc_join = ipv6_sock_mc_join,
.ipv6_sock_mc_drop = ipv6_sock_mc_drop,
- .ipv6_dst_lookup = ip6_dst_lookup,
+ .ipv6_dst_lookup_flow = ip6_dst_lookup_flow,
.udpv6_encap_enable = udpv6_encap_enable,
.ndisc_send_na = ndisc_send_na,
.nd_tbl = &nd_tbl,
@@ -588,16 +588,15 @@ static struct net_device *inet6_fib_lookup_dev(struct net *net,
struct net_device *dev;
struct dst_entry *dst;
struct flowi6 fl6;
- int err;
if (!ipv6_stub)
return ERR_PTR(-EAFNOSUPPORT);
memset(&fl6, 0, sizeof(fl6));
memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
- err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6);
- if (err)
- return ERR_PTR(err);
+ dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &fl6, NULL);
+ if (IS_ERR(dst))
+ return ERR_CAST(dst);
dev = dst->dev;
dev_hold(dev);
@@ -187,10 +187,13 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
.saddr = src->ipv6,
.flowi6_proto = IPPROTO_UDP
};
- err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
- &fl6);
- if (err)
+ ndst = ipv6_stub->ipv6_dst_lookup_flow(net,
+ ub->ubsock->sk,
+ &fl6, NULL);
+ if (IS_ERR(ndst)) {
+ err = PTR_ERR(ndst);
goto tx_error;
+ }
ttl = ip6_dst_hoplimit(ndst);
err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL,
&src->ipv6, &dst->ipv6, 0, ttl, 0,
--
2.17.1