dm init: fix max devices/targets checks

commit 8e890c1a upstream.

dm-init should allow up to DM_MAX_{DEVICES,TARGETS} for devices/targets,
and not DM_MAX_{DEVICES,TARGETS} - 1.

Fix the checks and also fix the error message when the number of devices
is surpassed.

Fixes: 6bbc923d ("dm: add support to directly boot to a mapped device")
Cc: stable@vger.kernel.org
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/md/dm-init.c

@@ -160,7 +160,7 @@ static int __init dm_parse_table(struct dm_device *dev, char *str)
 
 	while (table_entry) {
 		DMDEBUG("parsing table \"%s\"", str);
-		if (++dev->dmi.target_count >= DM_MAX_TARGETS) {
+		if (++dev->dmi.target_count > DM_MAX_TARGETS) {
 			DMERR("too many targets %u > %d",
 			      dev->dmi.target_count, DM_MAX_TARGETS);
 			return -EINVAL;
@@ -242,9 +242,9 @@ static int __init dm_parse_devices(struct list_head *devices, char *str)
 			return -ENOMEM;
 		list_add_tail(&dev->list, devices);
 
-		if (++ndev >= DM_MAX_DEVICES) {
-			DMERR("too many targets %u > %d",
-			      dev->dmi.target_count, DM_MAX_TARGETS);
+		if (++ndev > DM_MAX_DEVICES) {
+			DMERR("too many devices %lu > %d",
+			      ndev, DM_MAX_DEVICES);
 			return -EINVAL;
 		}