diff --git a/lib/libfdt/fdt.c b/lib/libfdt/fdt.c
index 6cf2fa0..9fe7cf4 100644
--- a/lib/libfdt/fdt.c
+++ b/lib/libfdt/fdt.c
@@ -22,6 +22,10 @@
 	if (can_assume(VALID_DTB))
 		return totalsize;
 
+	/* The device tree must be at an 8-byte aligned address */
+	if ((uintptr_t)fdt & 7)
+		return -FDT_ERR_ALIGNMENT;
+
 	if (fdt_magic(fdt) == FDT_MAGIC) {
 		/* Complete tree */
 		if (!can_assume(LATEST)) {
@@ -86,6 +90,10 @@
 {
 	size_t hdrsize;
 
+	/* The device tree must be at an 8-byte aligned address */
+	if ((uintptr_t)fdt & 7)
+		return -FDT_ERR_ALIGNMENT;
+
 	if (fdt_magic(fdt) != FDT_MAGIC)
 		return -FDT_ERR_BADMAGIC;
 	if (!can_assume(LATEST)) {
diff --git a/lib/libfdt/fdt_addresses.c b/lib/libfdt/fdt_addresses.c
index 9a82cd0..c40ba09 100644
--- a/lib/libfdt/fdt_addresses.c
+++ b/lib/libfdt/fdt_addresses.c
@@ -73,7 +73,7 @@
 	/* check validity of address */
 	prop = data;
 	if (addr_cells == 1) {
-		if ((addr > UINT32_MAX) || ((UINT32_MAX + 1 - addr) < size))
+		if ((addr > UINT32_MAX) || (((uint64_t) UINT32_MAX + 1 - addr) < size))
 			return -FDT_ERR_BADVALUE;
 
 		fdt32_st(prop, (uint32_t)addr);
diff --git a/lib/libfdt/fdt_overlay.c b/lib/libfdt/fdt_overlay.c
index d217e79..5c0c398 100644
--- a/lib/libfdt/fdt_overlay.c
+++ b/lib/libfdt/fdt_overlay.c
@@ -40,37 +40,22 @@
 	return fdt32_to_cpu(*val);
 }
 
-/**
- * overlay_get_target - retrieves the offset of a fragment's target
- * @fdt: Base device tree blob
- * @fdto: Device tree overlay blob
- * @fragment: node offset of the fragment in the overlay
- * @pathp: pointer which receives the path of the target (or NULL)
- *
- * overlay_get_target() retrieves the target offset in the base
- * device tree of a fragment, no matter how the actual targeting is
- * done (through a phandle or a path)
- *
- * returns:
- *      the targeted node offset in the base device tree
- *      Negative error code on error
- */
-static int overlay_get_target(const void *fdt, const void *fdto,
-			      int fragment, char const **pathp)
+int fdt_overlay_target_offset(const void *fdt, const void *fdto,
+			      int fragment_offset, char const **pathp)
 {
 	uint32_t phandle;
 	const char *path = NULL;
 	int path_len = 0, ret;
 
 	/* Try first to do a phandle based lookup */
-	phandle = overlay_get_target_phandle(fdto, fragment);
+	phandle = overlay_get_target_phandle(fdto, fragment_offset);
 	if (phandle == (uint32_t)-1)
 		return -FDT_ERR_BADPHANDLE;
 
 	/* no phandle, try path */
 	if (!phandle) {
 		/* And then a path based lookup */
-		path = fdt_getprop(fdto, fragment, "target-path", &path_len);
+		path = fdt_getprop(fdto, fragment_offset, "target-path", &path_len);
 		if (path)
 			ret = fdt_path_offset(fdt, path);
 		else
@@ -636,7 +621,7 @@
 		if (overlay < 0)
 			return overlay;
 
-		target = overlay_get_target(fdt, fdto, fragment, NULL);
+		target = fdt_overlay_target_offset(fdt, fdto, fragment, NULL);
 		if (target < 0)
 			return target;
 
@@ -779,7 +764,7 @@
 			return -FDT_ERR_BADOVERLAY;
 
 		/* get the target of the fragment */
-		ret = overlay_get_target(fdt, fdto, fragment, &target_path);
+		ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path);
 		if (ret < 0)
 			return ret;
 		target = ret;
@@ -801,7 +786,7 @@
 
 		if (!target_path) {
 			/* again in case setprop_placeholder changed it */
-			ret = overlay_get_target(fdt, fdto, fragment, &target_path);
+			ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path);
 			if (ret < 0)
 				return ret;
 			target = ret;
diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c
index 91cc6fe..9f6c551 100644
--- a/lib/libfdt/fdt_ro.c
+++ b/lib/libfdt/fdt_ro.c
@@ -181,8 +181,8 @@
 	if (!can_assume(VALID_INPUT) && !re)
 		return -FDT_ERR_BADOFFSET;
 
-	*address = fdt64_ld(&re->address);
-	*size = fdt64_ld(&re->size);
+	*address = fdt64_ld_(&re->address);
+	*size = fdt64_ld_(&re->size);
 	return 0;
 }
 
@@ -192,7 +192,7 @@
 	const struct fdt_reserve_entry *re;
 
 	for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
-		if (fdt64_ld(&re->size) == 0)
+		if (fdt64_ld_(&re->size) == 0)
 			return i;
 	}
 	return -FDT_ERR_TRUNCATED;
@@ -370,7 +370,7 @@
 	prop = fdt_offset_ptr_(fdt, offset);
 
 	if (lenp)
-		*lenp = fdt32_ld(&prop->len);
+		*lenp = fdt32_ld_(&prop->len);
 
 	return prop;
 }
@@ -408,7 +408,7 @@
 			offset = -FDT_ERR_INTERNAL;
 			break;
 		}
-		if (fdt_string_eq_(fdt, fdt32_ld(&prop->nameoff),
+		if (fdt_string_eq_(fdt, fdt32_ld_(&prop->nameoff),
 				   name, namelen)) {
 			if (poffset)
 				*poffset = offset;
@@ -461,7 +461,7 @@
 
 	/* Handle realignment */
 	if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
-	    (poffset + sizeof(*prop)) % 8 && fdt32_ld(&prop->len) >= 8)
+	    (poffset + sizeof(*prop)) % 8 && fdt32_ld_(&prop->len) >= 8)
 		return prop->data + 4;
 	return prop->data;
 }
@@ -479,22 +479,22 @@
 		int namelen;
 
 		if (!can_assume(VALID_INPUT)) {
-			name = fdt_get_string(fdt, fdt32_ld(&prop->nameoff),
+			name = fdt_get_string(fdt, fdt32_ld_(&prop->nameoff),
 					      &namelen);
+			*namep = name;
 			if (!name) {
 				if (lenp)
 					*lenp = namelen;
 				return NULL;
 			}
-			*namep = name;
 		} else {
-			*namep = fdt_string(fdt, fdt32_ld(&prop->nameoff));
+			*namep = fdt_string(fdt, fdt32_ld_(&prop->nameoff));
 		}
 	}
 
 	/* Handle realignment */
 	if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
-	    (offset + sizeof(*prop)) % 8 && fdt32_ld(&prop->len) >= 8)
+	    (offset + sizeof(*prop)) % 8 && fdt32_ld_(&prop->len) >= 8)
 		return prop->data + 4;
 	return prop->data;
 }
@@ -519,7 +519,7 @@
 			return 0;
 	}
 
-	return fdt32_ld(php);
+	return fdt32_ld_(php);
 }
 
 const char *fdt_get_alias_namelen(const void *fdt,
diff --git a/lib/libfdt/fdt_rw.c b/lib/libfdt/fdt_rw.c
index 68887b9..3621d36 100644
--- a/lib/libfdt/fdt_rw.c
+++ b/lib/libfdt/fdt_rw.c
@@ -349,7 +349,10 @@
 		return offset;
 
 	/* Try to place the new node after the parent's properties */
-	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
+	tag = fdt_next_tag(fdt, parentoffset, &nextoffset);
+	/* the fdt_subnode_offset_namelen() should ensure this never hits */
+	if (!can_assume(LIBFDT_FLAWLESS) && (tag != FDT_BEGIN_NODE))
+		return -FDT_ERR_INTERNAL;
 	do {
 		offset = nextoffset;
 		tag = fdt_next_tag(fdt, offset, &nextoffset);
@@ -391,7 +394,9 @@
 }
 
 static void fdt_packblocks_(const char *old, char *new,
-			    int mem_rsv_size, int struct_size)
+			    int mem_rsv_size,
+			    int struct_size,
+			    int strings_size)
 {
 	int mem_rsv_off, struct_off, strings_off;
 
@@ -406,8 +411,7 @@
 	fdt_set_off_dt_struct(new, struct_off);
 	fdt_set_size_dt_struct(new, struct_size);
 
-	memmove(new + strings_off, old + fdt_off_dt_strings(old),
-		fdt_size_dt_strings(old));
+	memmove(new + strings_off, old + fdt_off_dt_strings(old), strings_size);
 	fdt_set_off_dt_strings(new, strings_off);
 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
 }
@@ -428,12 +432,14 @@
 
 	if (can_assume(LATEST) || fdt_version(fdt) >= 17) {
 		struct_size = fdt_size_dt_struct(fdt);
-	} else {
+	} else if (fdt_version(fdt) == 16) {
 		struct_size = 0;
 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
 			;
 		if (struct_size < 0)
 			return struct_size;
+	} else {
+		return -FDT_ERR_BADVERSION;
 	}
 
 	if (can_assume(LIBFDT_ORDER) ||
@@ -465,7 +471,8 @@
 			return -FDT_ERR_NOSPACE;
 	}
 
-	fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size);
+	fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size,
+			fdt_size_dt_strings(fdt));
 	memmove(buf, tmp, newsize);
 
 	fdt_set_magic(buf, FDT_MAGIC);
@@ -485,7 +492,8 @@
 
 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
 		* sizeof(struct fdt_reserve_entry);
-	fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
+	fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt),
+			fdt_size_dt_strings(fdt));
 	fdt_set_totalsize(fdt, fdt_data_size_(fdt));
 
 	return 0;
diff --git a/lib/libfdt/fdt_strerror.c b/lib/libfdt/fdt_strerror.c
index b435693..d852b77 100644
--- a/lib/libfdt/fdt_strerror.c
+++ b/lib/libfdt/fdt_strerror.c
@@ -39,6 +39,7 @@
 	FDT_ERRTABENT(FDT_ERR_BADOVERLAY),
 	FDT_ERRTABENT(FDT_ERR_NOPHANDLES),
 	FDT_ERRTABENT(FDT_ERR_BADFLAGS),
+	FDT_ERRTABENT(FDT_ERR_ALIGNMENT),
 };
 #define FDT_ERRTABSIZE	((int)(sizeof(fdt_errtable) / sizeof(fdt_errtable[0])))
 
diff --git a/lib/libfdt/fdt_sw.c b/lib/libfdt/fdt_sw.c
index 68b543c..4c569ee 100644
--- a/lib/libfdt/fdt_sw.c
+++ b/lib/libfdt/fdt_sw.c
@@ -377,7 +377,7 @@
 	fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
 
 	/* And fix up fields that were keeping intermediate state. */
-	fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
+	fdt_set_last_comp_version(fdt, FDT_LAST_COMPATIBLE_VERSION);
 	fdt_set_magic(fdt, FDT_MAGIC);
 
 	return 0;
diff --git a/lib/libfdt/libfdt_internal.h b/lib/libfdt/libfdt_internal.h
index d4e0bd4..16bda19 100644
--- a/lib/libfdt/libfdt_internal.h
+++ b/lib/libfdt/libfdt_internal.h
@@ -46,6 +46,25 @@
 	return (void *)(uintptr_t)fdt_mem_rsv_(fdt, n);
 }
 
+/*
+ * Internal helpers to access tructural elements of the device tree
+ * blob (rather than for exaple reading integers from within property
+ * values).  We assume that we are either given a naturally aligned
+ * address for the platform or if we are not, we are on a platform
+ * where unaligned memory reads will be handled in a graceful manner.
+ * If not the external helpers fdtXX_ld() from libfdt.h can be used
+ * instead.
+ */
+static inline uint32_t fdt32_ld_(const fdt32_t *p)
+{
+	return fdt32_to_cpu(*p);
+}
+
+static inline uint64_t fdt64_ld_(const fdt64_t *p)
+{
+	return fdt64_to_cpu(*p);
+}
+
 #define FDT_SW_MAGIC		(~FDT_MAGIC)
 
 /**********************************************************************/