Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/include/net/dst.h b/include/net/dst.h
index fe62fe2..433f7c1 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -82,7 +82,7 @@
 struct dst_metrics {
 	u32		metrics[RTAX_MAX];
 	refcount_t	refcnt;
-};
+} __aligned(4);		/* Low pointer bits contain DST_METRICS_FLAGS */
 extern const struct dst_metrics dst_default_metrics;
 
 u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
@@ -401,7 +401,15 @@
 static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
 						     struct sk_buff *skb)
 {
-	struct neighbour *n =  dst->ops->neigh_lookup(dst, skb, NULL);
+	struct neighbour *n = NULL;
+
+	/* The packets from tunnel devices (eg bareudp) may have only
+	 * metadata in the dst pointer of skb. Hence a pointer check of
+	 * neigh_lookup is needed.
+	 */
+	if (dst->ops->neigh_lookup)
+		n = dst->ops->neigh_lookup(dst, skb, NULL);
+
 	return IS_ERR(n) ? NULL : n;
 }
 
@@ -516,7 +524,16 @@
 	struct dst_entry *dst = skb_dst(skb);
 
 	if (dst && dst->ops->update_pmtu)
-		dst->ops->update_pmtu(dst, NULL, skb, mtu);
+		dst->ops->update_pmtu(dst, NULL, skb, mtu, true);
+}
+
+/* update dst pmtu but not do neighbor confirm */
+static inline void skb_dst_update_pmtu_no_confirm(struct sk_buff *skb, u32 mtu)
+{
+	struct dst_entry *dst = skb_dst(skb);
+
+	if (dst && dst->ops->update_pmtu)
+		dst->ops->update_pmtu(dst, NULL, skb, mtu, false);
 }
 
 static inline void skb_tunnel_check_pmtu(struct sk_buff *skb,
@@ -526,7 +543,7 @@
 	u32 encap_mtu = dst_mtu(encap_dst);
 
 	if (skb->len > encap_mtu - headroom)
-		skb_dst_update_pmtu(skb, encap_mtu - headroom);
+		skb_dst_update_pmtu_no_confirm(skb, encap_mtu - headroom);
 }
 
 #endif /* _NET_DST_H */