From: Benedict Wong <benedictwong@xxxxxxxxxx>
[ Upstream commit a287f5b0cfc6804c5b12a4be13c7c9fe27869e90 ]
This change adds methods in the XFRM-I input path that ensures that
policies are checked prior to processing of the subsequent decapsulated
packet, after which the relevant policies may no longer be resolvable
(due to changing src/dst/proto/etc).
Notably, raw ESP/AH packets did not perform policy checks inherently,
whereas all other encapsulated packets (UDP, TCP encapsulated) do policy
checks after calling xfrm_input handling in the respective encapsulation
layer.
Fixes: b0355dbbf13c ("Fix XFRM-I support for nested ESP tunnels")
Test: Verified with additional Android Kernel Unit tests
Test: Verified against Android CTS
Signed-off-by: Benedict Wong <benedictwong@xxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/xfrm/xfrm_interface_core.c | 54 +++++++++++++++++++++++++++++++---
1 file changed, 50 insertions(+), 4 deletions(-)
diff --git a/net/xfrm/xfrm_interface_core.c b/net/xfrm/xfrm_interface_core.c
index 5a67b120c4dbd..94a3609548b11 100644
--- a/net/xfrm/xfrm_interface_core.c
+++ b/net/xfrm/xfrm_interface_core.c
@@ -310,6 +310,52 @@ static void xfrmi_scrub_packet(struct sk_buff *skb, bool xnet)
skb->mark = 0;
}
+static int xfrmi_input(struct sk_buff *skb, int nexthdr, __be32 spi,
+ int encap_type, unsigned short family)
+{
+ struct sec_path *sp;
+
+ sp = skb_sec_path(skb);
+ if (sp && (sp->len || sp->olen) &&
+ !xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family))
+ goto discard;
+
+ XFRM_SPI_SKB_CB(skb)->family = family;
+ if (family == AF_INET) {
+ XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
+ } else {
+ XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
+ }
+
+ return xfrm_input(skb, nexthdr, spi, encap_type);
+discard:
+ kfree_skb(skb);
+ return 0;
+}
+
+static int xfrmi4_rcv(struct sk_buff *skb)
+{
+ return xfrmi_input(skb, ip_hdr(skb)->protocol, 0, 0, AF_INET);
+}
+
+static int xfrmi6_rcv(struct sk_buff *skb)
+{
+ return xfrmi_input(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
+ 0, 0, AF_INET6);
+}
+
+static int xfrmi4_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
+{
+ return xfrmi_input(skb, nexthdr, spi, encap_type, AF_INET);
+}
+
+static int xfrmi6_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
+{
+ return xfrmi_input(skb, nexthdr, spi, encap_type, AF_INET6);
+}
+
static int xfrmi_rcv_cb(struct sk_buff *skb, int err)
{
const struct xfrm_mode *inner_mode;
@@ -937,8 +983,8 @@ static struct pernet_operations xfrmi_net_ops = {
};
static struct xfrm6_protocol xfrmi_esp6_protocol __read_mostly = {
- .handler = xfrm6_rcv,
- .input_handler = xfrm_input,
+ .handler = xfrmi6_rcv,
+ .input_handler = xfrmi6_input,
.cb_handler = xfrmi_rcv_cb,
.err_handler = xfrmi6_err,
.priority = 10,
@@ -988,8 +1034,8 @@ static struct xfrm6_tunnel xfrmi_ip6ip_handler __read_mostly = {
#endif
static struct xfrm4_protocol xfrmi_esp4_protocol __read_mostly = {
- .handler = xfrm4_rcv,
- .input_handler = xfrm_input,
+ .handler = xfrmi4_rcv,
+ .input_handler = xfrmi4_input,
.cb_handler = xfrmi_rcv_cb,
.err_handler = xfrmi4_err,
.priority = 10,
--
2.39.2
