Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index f86f948..b71b836 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -355,7 +355,7 @@
 
 	csum = skb_copy_and_csum_bits(icmp_param->skb,
 				      icmp_param->offset + offset,
-				      to, len, 0);
+				      to, len);
 
 	skb->csum = csum_block_add(skb->csum, csum, odd);
 	if (icmp_pointers[icmp_param->data.icmph.type].error)
@@ -379,15 +379,15 @@
 		ip_flush_pending_frames(sk);
 	} else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
 		struct icmphdr *icmph = icmp_hdr(skb);
-		__wsum csum = 0;
+		__wsum csum;
 		struct sk_buff *skb1;
 
+		csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
+						 (char *)icmph,
+						 icmp_param->head_len);
 		skb_queue_walk(&sk->sk_write_queue, skb1) {
 			csum = csum_add(csum, skb1->csum);
 		}
-		csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
-						 (char *)icmph,
-						 icmp_param->head_len, csum);
 		icmph->checksum = csum_fold(csum);
 		skb->ip_summed = CHECKSUM_NONE;
 		ip_push_pending_frames(sk, fl4);
@@ -705,15 +705,16 @@
 			dev = dev_get_by_index_rcu(net, inet_iif(skb_in));
 
 		if (dev)
-			saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK);
+			saddr = inet_select_addr(dev, iph->saddr,
+						 RT_SCOPE_LINK);
 		else
 			saddr = 0;
 		rcu_read_unlock();
 	}
 
-	tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
+	tos = icmp_pointers[type].error ? (RT_TOS(iph->tos) |
 					   IPTOS_PREC_INTERNETCONTROL) :
-					  iph->tos;
+					   iph->tos;
 	mark = IP4_REPLY_MARK(net, skb_in->mark);
 
 	if (__ip_options_echo(net, &icmp_param.replyopts.opt.opt, skb_in, opt))
@@ -813,7 +814,7 @@
 
 static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
 {
-	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	const struct iphdr *iph = (const struct iphdr *)skb->data;
 	const struct net_protocol *ipprot;
 	int protocol = iph->protocol;
 
@@ -882,7 +883,7 @@
 		case ICMP_FRAG_NEEDED:
 			/* for documentation of the ip_no_pmtu_disc
 			 * values please see
-			 * Documentation/networking/ip-sysctl.txt
+			 * Documentation/networking/ip-sysctl.rst
 			 */
 			switch (net->ipv4.sysctl_ip_no_pmtu_disc) {
 			default:
@@ -894,7 +895,7 @@
 			case 3:
 				if (!icmp_tag_validation(iph->protocol))
 					goto out;
-				/* fall through */
+				fallthrough;
 			case 0:
 				info = ntohs(icmph->un.frag.mtu);
 			}
@@ -1145,6 +1146,65 @@
 	goto drop;
 }
 
+static bool ip_icmp_error_rfc4884_validate(const struct sk_buff *skb, int off)
+{
+	struct icmp_extobj_hdr *objh, _objh;
+	struct icmp_ext_hdr *exth, _exth;
+	u16 olen;
+
+	exth = skb_header_pointer(skb, off, sizeof(_exth), &_exth);
+	if (!exth)
+		return false;
+	if (exth->version != 2)
+		return true;
+
+	if (exth->checksum &&
+	    csum_fold(skb_checksum(skb, off, skb->len - off, 0)))
+		return false;
+
+	off += sizeof(_exth);
+	while (off < skb->len) {
+		objh = skb_header_pointer(skb, off, sizeof(_objh), &_objh);
+		if (!objh)
+			return false;
+
+		olen = ntohs(objh->length);
+		if (olen < sizeof(_objh))
+			return false;
+
+		off += olen;
+		if (off > skb->len)
+			return false;
+	}
+
+	return true;
+}
+
+void ip_icmp_error_rfc4884(const struct sk_buff *skb,
+			   struct sock_ee_data_rfc4884 *out,
+			   int thlen, int off)
+{
+	int hlen;
+
+	/* original datagram headers: end of icmph to payload (skb->data) */
+	hlen = -skb_transport_offset(skb) - thlen;
+
+	/* per rfc 4884: minimal datagram length of 128 bytes */
+	if (off < 128 || off < hlen)
+		return;
+
+	/* kernel has stripped headers: return payload offset in bytes */
+	off -= hlen;
+	if (off + sizeof(struct icmp_ext_hdr) > skb->len)
+		return;
+
+	out->len = off;
+
+	if (!ip_icmp_error_rfc4884_validate(skb, off))
+		out->flags |= SO_EE_RFC4884_FLAG_INVALID;
+}
+EXPORT_SYMBOL_GPL(ip_icmp_error_rfc4884);
+
 int icmp_err(struct sk_buff *skb, u32 info)
 {
 	struct iphdr *iph = (struct iphdr *)skb->data;