base: soc: Check for NULL SoC device attributes

If soc_device_match() is used to check the value of a specific
attribute that is not present for the current SoC, the kernel crashes
with a NULL pointer dereference.

Fix this by explicitly checking for the absence of a needed property,
and considering this a non-match.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/soc.c

@@ -176,19 +176,23 @@ static int soc_device_match_one(struct device *dev, void *arg)
 	const struct soc_device_attribute *match = arg;
 
 	if (match->machine &&
-	    !glob_match(match->machine, soc_dev->attr->machine))
+	    (!soc_dev->attr->machine ||
+	     !glob_match(match->machine, soc_dev->attr->machine)))
 		return 0;
 
 	if (match->family &&
-	    !glob_match(match->family, soc_dev->attr->family))
+	    (!soc_dev->attr->family ||
+	     !glob_match(match->family, soc_dev->attr->family)))
 		return 0;
 
 	if (match->revision &&
-	    !glob_match(match->revision, soc_dev->attr->revision))
+	    (!soc_dev->attr->revision ||
+	     !glob_match(match->revision, soc_dev->attr->revision)))
 		return 0;
 
 	if (match->soc_id &&
-	    !glob_match(match->soc_id, soc_dev->attr->soc_id))
+	    (!soc_dev->attr->soc_id ||
+	     !glob_match(match->soc_id, soc_dev->attr->soc_id)))
 		return 0;
 
 	return 1;