Merge tag 'ipsec-next-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next

Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2023-10-28

1) Remove unused function declarations of xfrm4_extract_input and
   xfrm6_extract_input. From Yue Haibing.

2) Annotate struct xfrm_sec_ctx with __counted_by.
   From Kees Cook.

3) Support GRO decapsulation for ESP in UDP encapsulation.
   From Antony Antony et all.

4) Replace the xfrm session decode with flow dissector.
   From Florian Westphal.

5) Fix a use after free in __xfrm6_udp_encap_rcv.

6) Fix the layer 4 flowi decoding.
   From Florian Westphal.

* tag 'ipsec-next-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next:
  xfrm: policy: fix layer 4 flowi decoding
  xfrm Fix use after free in __xfrm6_udp_encap_rcv.
  xfrm: policy: replace session decode with flow dissector
  xfrm: move mark and oif flowi decode into common code
  xfrm: pass struct net to xfrm_decode_session wrappers
  xfrm: Support GRO for IPv6 ESP in UDP encapsulation
  xfrm: Support GRO for IPv4 ESP in UDP encapsulation
  xfrm: Use the XFRM_GRO to indicate a GRO call on input
  xfrm: Annotate struct xfrm_sec_ctx with __counted_by
  xfrm: Remove unused function declarations
====================

Link: https://lore.kernel.org/r/20231028084328.3119236-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

6 files changed, 102 insertions, 23 deletions

diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c
index 10e96ed6c9e3..b3271957ad9a 100644
--- a/net/ipv4/esp4_offload.c
+++ b/net/ipv4/esp4_offload.c
@@ -33,6 +33,7 @@ static struct sk_buff *esp4_gro_receive(struct list_head *head,
 	int offset = skb_gro_offset(skb);
 	struct xfrm_offload *xo;
 	struct xfrm_state *x;
+	int encap_type = 0;
 	__be32 seq;
 	__be32 spi;
 
@@ -70,6 +71,9 @@ static struct sk_buff *esp4_gro_receive(struct list_head *head,
 
 	xo->flags |= XFRM_GRO;
 
+	if (NAPI_GRO_CB(skb)->proto == IPPROTO_UDP)
+		encap_type = UDP_ENCAP_ESPINUDP;
+
 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
@@ -77,7 +81,7 @@ static struct sk_buff *esp4_gro_receive(struct list_head *head,
 
 	/* We don't need to handle errors from xfrm_input, it does all
 	 * the error handling and frees the resources on error. */
-	xfrm_input(skb, IPPROTO_ESP, spi, -2);
+	xfrm_input(skb, IPPROTO_ESP, spi, encap_type);
 
 	return ERR_PTR(-EINPROGRESS);
 out_reset:
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index b8607763d113..e63a3bf99617 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -517,7 +517,7 @@ static struct rtable *icmp_route_lookup(struct net *net,
 	} else
 		return rt;
 
-	err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET);
+	err = xfrm_decode_session_reverse(net, skb_in, flowi4_to_flowi(&fl4_dec), AF_INET);
 	if (err)
 		goto relookup_failed;
 
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index d1e7d0ceb7ed..9ab9b3ebe0cd 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -288,11 +288,11 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 	switch (skb->protocol) {
 	case htons(ETH_P_IP):
 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
-		xfrm_decode_session(skb, &fl, AF_INET);
+		xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET);
 		break;
 	case htons(ETH_P_IPV6):
 		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
-		xfrm_decode_session(skb, &fl, AF_INET6);
+		xfrm_decode_session(dev_net(dev), skb, &fl, AF_INET6);
 		break;
 	default:
 		goto tx_err;
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index bd135165482a..591a2737808e 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -62,7 +62,7 @@ int ip_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb, un
 
 #ifdef CONFIG_XFRM
 	if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
-	    xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) {
+	    xfrm_decode_session(net, skb, flowi4_to_flowi(&fl4), AF_INET) == 0) {
 		struct dst_entry *dst = skb_dst(skb);
 		skb_dst_set(skb, NULL);
 		dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0);
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 1734fd6a1ce0..89e5a806b82e 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2630,6 +2630,19 @@ void udp_destroy_sock(struct sock *sk)
 	}
 }
 
+static void set_xfrm_gro_udp_encap_rcv(__u16 encap_type, unsigned short family,
+				       struct sock *sk)
+{
+#ifdef CONFIG_XFRM
+	if (udp_test_bit(GRO_ENABLED, sk) && encap_type == UDP_ENCAP_ESPINUDP) {
+		if (family == AF_INET)
+			WRITE_ONCE(udp_sk(sk)->gro_receive, xfrm4_gro_udp_encap_rcv);
+		else if (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6)
+			WRITE_ONCE(udp_sk(sk)->gro_receive, ipv6_stub->xfrm6_gro_udp_encap_rcv);
+	}
+#endif
+}
+
 /*
  *	Socket option code for UDP
  */
@@ -2679,6 +2692,8 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 		case 0:
 #ifdef CONFIG_XFRM
 		case UDP_ENCAP_ESPINUDP:
+			set_xfrm_gro_udp_encap_rcv(val, sk->sk_family, sk);
+			fallthrough;
 		case UDP_ENCAP_ESPINUDP_NON_IKE:
 #if IS_ENABLED(CONFIG_IPV6)
 			if (sk->sk_family == AF_INET6)
@@ -2721,6 +2736,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 			udp_tunnel_encap_enable(sk);
 		udp_assign_bit(GRO_ENABLED, sk, valbool);
 		udp_assign_bit(ACCEPT_L4, sk, valbool);
+		set_xfrm_gro_udp_encap_rcv(up->encap_type, sk->sk_family, sk);
 		break;
 
 	/*
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
index 183f6dc37242..c54676998eb6 100644
--- a/net/ipv4/xfrm4_input.c
+++ b/net/ipv4/xfrm4_input.c
@@ -17,6 +17,8 @@
 #include <linux/netfilter_ipv4.h>
 #include <net/ip.h>
 #include <net/xfrm.h>
+#include <net/protocol.h>
+#include <net/gro.h>
 
 static int xfrm4_rcv_encap_finish2(struct net *net, struct sock *sk,
 				   struct sk_buff *skb)
@@ -72,14 +74,7 @@ int xfrm4_transport_finish(struct sk_buff *skb, int async)
 	return 0;
 }
 
-/* If it's a keepalive packet, then just eat it.
- * If it's an encapsulated packet, then pass it to the
- * IPsec xfrm input.
- * Returns 0 if skb passed to xfrm or was dropped.
- * Returns >0 if skb should be passed to UDP.
- * Returns <0 if skb should be resubmitted (-ret is protocol)
- */
-int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
+static int __xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb, bool pull)
 {
 	struct udp_sock *up = udp_sk(sk);
 	struct udphdr *uh;
@@ -110,7 +105,7 @@ int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 	case UDP_ENCAP_ESPINUDP:
 		/* Check if this is a keepalive packet.  If so, eat it. */
 		if (len == 1 && udpdata[0] == 0xff) {
-			goto drop;
+			return -EINVAL;
 		} else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
 			/* ESP Packet without Non-ESP header */
 			len = sizeof(struct udphdr);
@@ -121,7 +116,7 @@ int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 	case UDP_ENCAP_ESPINUDP_NON_IKE:
 		/* Check if this is a keepalive packet.  If so, eat it. */
 		if (len == 1 && udpdata[0] == 0xff) {
-			goto drop;
+			return -EINVAL;
 		} else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
 			   udpdata32[0] == 0 && udpdata32[1] == 0) {
 
@@ -139,7 +134,7 @@ int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 	 * protocol to ESP, and then call into the transform receiver.
 	 */
 	if (skb_unclone(skb, GFP_ATOMIC))
-		goto drop;
+		return -EINVAL;
 
 	/* Now we can update and verify the packet length... */
 	iph = ip_hdr(skb);
@@ -147,25 +142,89 @@ int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 	iph->tot_len = htons(ntohs(iph->tot_len) - len);
 	if (skb->len < iphlen + len) {
 		/* packet is too small!?! */
-		goto drop;
+		return -EINVAL;
 	}
 
 	/* pull the data buffer up to the ESP header and set the
 	 * transport header to point to ESP.  Keep UDP on the stack
 	 * for later.
 	 */
-	__skb_pull(skb, len);
-	skb_reset_transport_header(skb);
+	if (pull) {
+		__skb_pull(skb, len);
+		skb_reset_transport_header(skb);
+	} else {
+		skb_set_transport_header(skb, len);
+	}
 
 	/* process ESP */
-	return xfrm4_rcv_encap(skb, IPPROTO_ESP, 0, encap_type);
-
-drop:
-	kfree_skb(skb);
 	return 0;
 }
+
+/* If it's a keepalive packet, then just eat it.
+ * If it's an encapsulated packet, then pass it to the
+ * IPsec xfrm input.
+ * Returns 0 if skb passed to xfrm or was dropped.
+ * Returns >0 if skb should be passed to UDP.
+ * Returns <0 if skb should be resubmitted (-ret is protocol)
+ */
+int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	int ret;
+
+	ret = __xfrm4_udp_encap_rcv(sk, skb, true);
+	if (!ret)
+		return xfrm4_rcv_encap(skb, IPPROTO_ESP, 0,
+				       udp_sk(sk)->encap_type);
+
+	if (ret < 0) {
+		kfree_skb(skb);
+		return 0;
+	}
+
+	return ret;
+}
 EXPORT_SYMBOL(xfrm4_udp_encap_rcv);
 
+struct sk_buff *xfrm4_gro_udp_encap_rcv(struct sock *sk, struct list_head *head,
+					struct sk_buff *skb)
+{
+	int offset = skb_gro_offset(skb);
+	const struct net_offload *ops;
+	struct sk_buff *pp = NULL;
+	int ret;
+
+	offset = offset - sizeof(struct udphdr);
+
+	if (!pskb_pull(skb, offset))
+		return NULL;
+
+	rcu_read_lock();
+	ops = rcu_dereference(inet_offloads[IPPROTO_ESP]);
+	if (!ops || !ops->callbacks.gro_receive)
+		goto out;
+
+	ret = __xfrm4_udp_encap_rcv(sk, skb, false);
+	if (ret)
+		goto out;
+
+	skb_push(skb, offset);
+	NAPI_GRO_CB(skb)->proto = IPPROTO_UDP;
+
+	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
+	rcu_read_unlock();
+
+	return pp;
+
+out:
+	rcu_read_unlock();
+	skb_push(skb, offset);
+	NAPI_GRO_CB(skb)->same_flow = 0;
+	NAPI_GRO_CB(skb)->flush = 1;
+
+	return NULL;
+}
+EXPORT_SYMBOL(xfrm4_gro_udp_encap_rcv);
+
 int xfrm4_rcv(struct sk_buff *skb)
 {
 	return xfrm4_rcv_spi(skb, ip_hdr(skb)->protocol, 0);