diff --git a/drivers/firmware/dmi-id.c b/drivers/firmware/dmi-id.c
index dc269cb288c2..951b6c79f166 100644
--- a/drivers/firmware/dmi-id.c
+++ b/drivers/firmware/dmi-id.c
@@ -47,7 +47,7 @@ DEFINE_DMI_ATTR_WITH_SHOW(product_name,		0444, DMI_PRODUCT_NAME);
 DEFINE_DMI_ATTR_WITH_SHOW(product_version,	0444, DMI_PRODUCT_VERSION);
 DEFINE_DMI_ATTR_WITH_SHOW(product_serial,	0400, DMI_PRODUCT_SERIAL);
 DEFINE_DMI_ATTR_WITH_SHOW(product_uuid,		0400, DMI_PRODUCT_UUID);
-DEFINE_DMI_ATTR_WITH_SHOW(product_family,	0400, DMI_PRODUCT_FAMILY);
+DEFINE_DMI_ATTR_WITH_SHOW(product_family,	0444, DMI_PRODUCT_FAMILY);
 DEFINE_DMI_ATTR_WITH_SHOW(board_vendor,		0444, DMI_BOARD_VENDOR);
 DEFINE_DMI_ATTR_WITH_SHOW(board_name,		0444, DMI_BOARD_NAME);
 DEFINE_DMI_ATTR_WITH_SHOW(board_version,	0444, DMI_BOARD_VERSION);
@@ -192,7 +192,7 @@ static void __init dmi_id_init_attr_table(void)
 	ADD_DMI_ATTR(product_version,   DMI_PRODUCT_VERSION);
 	ADD_DMI_ATTR(product_serial,    DMI_PRODUCT_SERIAL);
 	ADD_DMI_ATTR(product_uuid,      DMI_PRODUCT_UUID);
-	ADD_DMI_ATTR(product_family,      DMI_PRODUCT_FAMILY);
+	ADD_DMI_ATTR(product_family,    DMI_PRODUCT_FAMILY);
 	ADD_DMI_ATTR(board_vendor,      DMI_BOARD_VENDOR);
 	ADD_DMI_ATTR(board_name,        DMI_BOARD_NAME);
 	ADD_DMI_ATTR(board_version,     DMI_BOARD_VERSION);
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 93f7acdaac7a..783041964439 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -144,7 +144,7 @@ static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
 
 	buf = dmi_early_remap(dmi_base, orig_dmi_len);
 	if (buf == NULL)
-		return -1;
+		return -ENOMEM;
 
 	dmi_decode_table(buf, decode, NULL);
 
@@ -178,7 +178,7 @@ static void __init dmi_save_ident(const struct dmi_header *dm, int slot,
 	const char *d = (const char *) dm;
 	const char *p;
 
-	if (dmi_ident[slot])
+	if (dmi_ident[slot] || dm->length <= string)
 		return;
 
 	p = dmi_string(dm, d[string]);
@@ -191,13 +191,14 @@ static void __init dmi_save_ident(const struct dmi_header *dm, int slot,
 static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
 		int index)
 {
-	const u8 *d = (u8 *) dm + index;
+	const u8 *d;
 	char *s;
 	int is_ff = 1, is_00 = 1, i;
 
-	if (dmi_ident[slot])
+	if (dmi_ident[slot] || dm->length <= index + 16)
 		return;
 
+	d = (u8 *) dm + index;
 	for (i = 0; i < 16 && (is_ff || is_00); i++) {
 		if (d[i] != 0x00)
 			is_00 = 0;
@@ -228,16 +229,17 @@ static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
 static void __init dmi_save_type(const struct dmi_header *dm, int slot,
 		int index)
 {
-	const u8 *d = (u8 *) dm + index;
+	const u8 *d;
 	char *s;
 
-	if (dmi_ident[slot])
+	if (dmi_ident[slot] || dm->length <= index)
 		return;
 
 	s = dmi_alloc(4);
 	if (!s)
 		return;
 
+	d = (u8 *) dm + index;
 	sprintf(s, "%u", *d & 0x7F);
 	dmi_ident[slot] = s;
 }
@@ -278,9 +280,13 @@ static void __init dmi_save_devices(const struct dmi_header *dm)
 
 static void __init dmi_save_oem_strings_devices(const struct dmi_header *dm)
 {
-	int i, count = *(u8 *)(dm + 1);
+	int i, count;
 	struct dmi_device *dev;
 
+	if (dm->length < 0x05)
+		return;
+
+	count = *(u8 *)(dm + 1);
 	for (i = 1; i <= count; i++) {
 		const char *devname = dmi_string(dm, i);
 
@@ -353,6 +359,9 @@ static void __init dmi_save_extended_devices(const struct dmi_header *dm)
 	const char *name;
 	const u8 *d = (u8 *)dm;
 
+	if (dm->length < 0x0B)
+		return;
+
 	/* Skip disabled device */
 	if ((d[0x5] & 0x80) == 0)
 		return;
@@ -387,7 +396,7 @@ static void __init save_mem_devices(const struct dmi_header *dm, void *v)
 	const char *d = (const char *)dm;
 	static int nr;
 
-	if (dm->type != DMI_ENTRY_MEM_DEVICE)
+	if (dm->type != DMI_ENTRY_MEM_DEVICE || dm->length < 0x12)
 		return;
 	if (nr >= dmi_memdev_nr) {
 		pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");
@@ -649,6 +658,21 @@ void __init dmi_scan_machine(void)
 		if (p == NULL)
 			goto error;
 
+		/*
+		 * Same logic as above, look for a 64-bit entry point
+		 * first, and if not found, fall back to 32-bit entry point.
+		 */
+		memcpy_fromio(buf, p, 16);
+		for (q = p + 16; q < p + 0x10000; q += 16) {
+			memcpy_fromio(buf + 16, q, 16);
+			if (!dmi_smbios3_present(buf)) {
+				dmi_available = 1;
+				dmi_early_unmap(p, 0x10000);
+				goto out;
+			}
+			memcpy(buf, buf + 16, 16);
+		}
+
 		/*
 		 * Iterate over all possible DMI header addresses q.
 		 * Maintain the 32 bytes around q in buf.  On the
@@ -659,7 +683,7 @@ void __init dmi_scan_machine(void)
 		memset(buf, 0, 16);
 		for (q = p; q < p + 0x10000; q += 16) {
 			memcpy_fromio(buf + 16, q, 16);
-			if (!dmi_smbios3_present(buf) || !dmi_present(buf)) {
+			if (!dmi_present(buf)) {
 				dmi_available = 1;
 				dmi_early_unmap(p, 0x10000);
 				goto out;
@@ -993,7 +1017,8 @@ EXPORT_SYMBOL(dmi_get_date);
  *	@decode: Callback function
  *	@private_data: Private data to be passed to the callback function
  *
- *	Returns -1 when the DMI table can't be reached, 0 on success.
+ *	Returns 0 on success, -ENXIO if DMI is not selected or not present,
+ *	or a different negative error code if DMI walking fails.
  */
 int dmi_walk(void (*decode)(const struct dmi_header *, void *),
 	     void *private_data)
@@ -1001,11 +1026,11 @@ int dmi_walk(void (*decode)(const struct dmi_header *, void *),
 	u8 *buf;
 
 	if (!dmi_available)
-		return -1;
+		return -ENXIO;
 
 	buf = dmi_remap(dmi_base, dmi_len);
 	if (buf == NULL)
-		return -1;
+		return -ENOMEM;
 
 	dmi_decode_table(buf, decode, private_data);
 
diff --git a/include/linux/dmi.h b/include/linux/dmi.h
index 5e9c74cf8894..9bbf21a516e4 100644
--- a/include/linux/dmi.h
+++ b/include/linux/dmi.h
@@ -136,7 +136,7 @@ static inline int dmi_name_in_vendors(const char *s) { return 0; }
 static inline int dmi_name_in_serial(const char *s) { return 0; }
 #define dmi_available 0
 static inline int dmi_walk(void (*decode)(const struct dmi_header *, void *),
-	void *private_data) { return -1; }
+	void *private_data) { return -ENXIO; }
 static inline bool dmi_match(enum dmi_field f, const char *str)
 	{ return false; }
 static inline void dmi_memdev_name(u16 handle, const char **bank,