Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 9768901..5c96776 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #define pr_fmt(fmt) "IPsec: " fmt
 
 #include <crypto/aead.h>
@@ -32,8 +33,6 @@
 
 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
 
-static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
-
 /*
  * Allocate an AEAD request structure with extra space for SG and IV.
  *
@@ -125,10 +124,13 @@
 	void *tmp;
 	struct xfrm_state *x;
 
-	if (xo && (xo->flags & XFRM_DEV_RESUME))
-		x = skb->sp->xvec[skb->sp->len - 1];
-	else
+	if (xo && (xo->flags & XFRM_DEV_RESUME)) {
+		struct sec_path *sp = skb_sec_path(skb);
+
+		x = sp->xvec[sp->len - 1];
+	} else {
 		x = skb_dst(skb)->xfrm;
+	}
 
 	tmp = ESP_SKB_CB(skb)->tmp;
 	esp_ssg_unref(x, tmp);
@@ -223,7 +225,7 @@
 	tail[plen - 1] = proto;
 }
 
-static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
+static int esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
 {
 	int encap_type;
 	struct udphdr *uh;
@@ -231,6 +233,7 @@
 	__be16 sport, dport;
 	struct xfrm_encap_tmpl *encap = x->encap;
 	struct ip_esp_hdr *esph = esp->esph;
+	unsigned int len;
 
 	spin_lock_bh(&x->lock);
 	sport = encap->encap_sport;
@@ -238,11 +241,14 @@
 	encap_type = encap->encap_type;
 	spin_unlock_bh(&x->lock);
 
+	len = skb->len + esp->tailen - skb_transport_offset(skb);
+	if (len + sizeof(struct iphdr) >= IP_MAX_MTU)
+		return -EMSGSIZE;
+
 	uh = (struct udphdr *)esph;
 	uh->source = sport;
 	uh->dest = dport;
-	uh->len = htons(skb->len + esp->tailen
-		  - skb_transport_offset(skb));
+	uh->len = htons(len);
 	uh->check = 0;
 
 	switch (encap_type) {
@@ -259,6 +265,8 @@
 
 	*skb_mac_header(skb) = IPPROTO_UDP;
 	esp->esph = esph;
+
+	return 0;
 }
 
 int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
@@ -272,8 +280,12 @@
 	int tailen = esp->tailen;
 
 	/* this is non-NULL only with UDP Encapsulation */
-	if (x->encap)
-		esp_output_udp_encap(x, skb, esp);
+	if (x->encap) {
+		int err = esp_output_udp_encap(x, skb, esp);
+
+		if (err < 0)
+			return err;
+	}
 
 	if (!skb_cloned(skb)) {
 		if (tailen <= skb_tailroom(skb)) {
@@ -325,7 +337,7 @@
 			skb->len += tailen;
 			skb->data_len += tailen;
 			skb->truesize += tailen;
-			if (sk)
+			if (sk && sk_fullsock(sk))
 				refcount_add(tailen, &sk->sk_wmem_alloc);
 
 			goto out;
@@ -492,7 +504,7 @@
 		struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
 		u32 padto;
 
-		padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
+		padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
 		if (skb->len < padto)
 			esp.tfclen = padto - skb->len;
 	}
@@ -683,12 +695,11 @@
  */
 static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
 {
-	struct ip_esp_hdr *esph;
 	struct crypto_aead *aead = x->data;
 	struct aead_request *req;
 	struct sk_buff *trailer;
 	int ivlen = crypto_aead_ivsize(aead);
-	int elen = skb->len - sizeof(*esph) - ivlen;
+	int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
 	int nfrags;
 	int assoclen;
 	int seqhilen;
@@ -698,13 +709,13 @@
 	struct scatterlist *sg;
 	int err = -EINVAL;
 
-	if (!pskb_may_pull(skb, sizeof(*esph) + ivlen))
+	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen))
 		goto out;
 
 	if (elen <= 0)
 		goto out;
 
-	assoclen = sizeof(*esph);
+	assoclen = sizeof(struct ip_esp_hdr);
 	seqhilen = 0;
 
 	if (x->props.flags & XFRM_STATE_ESN) {
@@ -775,28 +786,6 @@
 	return err;
 }
 
-static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
-{
-	struct crypto_aead *aead = x->data;
-	u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
-	unsigned int net_adj;
-
-	switch (x->props.mode) {
-	case XFRM_MODE_TRANSPORT:
-	case XFRM_MODE_BEET:
-		net_adj = sizeof(struct iphdr);
-		break;
-	case XFRM_MODE_TUNNEL:
-		net_adj = 0;
-		break;
-	default:
-		BUG();
-	}
-
-	return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
-		 net_adj) & ~(blksize - 1)) + net_adj - 2;
-}
-
 static int esp4_err(struct sk_buff *skb, u32 info)
 {
 	struct net *net = dev_net(skb->dev);
@@ -820,9 +809,9 @@
 		return 0;
 
 	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
-		ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
+		ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP);
 	else
-		ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
+		ipv4_redirect(skb, net, 0, IPPROTO_ESP);
 	xfrm_state_put(x);
 
 	return 0;
@@ -1022,7 +1011,6 @@
 	.flags		= XFRM_TYPE_REPLAY_PROT,
 	.init_state	= esp_init_state,
 	.destructor	= esp_destroy,
-	.get_mtu	= esp4_get_mtu,
 	.input		= esp_input,
 	.output		= esp_output,
 };
@@ -1053,8 +1041,7 @@
 {
 	if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
 		pr_info("%s: can't remove protocol\n", __func__);
-	if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
-		pr_info("%s: can't remove xfrm type\n", __func__);
+	xfrm_unregister_type(&esp_type, AF_INET);
 }
 
 module_init(esp4_init);