From 3908c9839b1077e677ef9e92d2bce7f224519c59 Mon Sep 17 00:00:00 2001
From: Damien Le Moal <damien.lemoal@wdc.com>
Date: Mon, 3 Jul 2017 15:44:58 +0900
Subject: [PATCH] dm zoned: fix overflow when converting zone ID to sectors
Git-commit: 3908c9839b1077e677ef9e92d2bce7f224519c59
Patch-mainline: v4.13-rc1
References: fate#322738,fate#322919,fate#322950,fate#323773

A zone ID is a 32 bits unsigned int which can overflow when doing the
bit shifts in dmz_start_sect().  With a 256 MB zone size drive, the
overflow happens for a zone ID >= 8192.

Fix this by casting the zone ID to a sector_t before doing the bit
shift.  While at it, similarly fix dmz_start_block().

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/dm-zoned-metadata.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 4618441cc412..884ff7c170a0 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -191,12 +191,12 @@ unsigned int dmz_id(struct dmz_metadata *zmd, struct dm_zone *zone)
 
 sector_t dmz_start_sect(struct dmz_metadata *zmd, struct dm_zone *zone)
 {
-	return dmz_id(zmd, zone) << zmd->dev->zone_nr_sectors_shift;
+	return (sector_t)dmz_id(zmd, zone) << zmd->dev->zone_nr_sectors_shift;
 }
 
 sector_t dmz_start_block(struct dmz_metadata *zmd, struct dm_zone *zone)
 {
-	return dmz_id(zmd, zone) << zmd->dev->zone_nr_blocks_shift;
+	return (sector_t)dmz_id(zmd, zone) << zmd->dev->zone_nr_blocks_shift;
 }
 
 unsigned int dmz_nr_chunks(struct dmz_metadata *zmd)
-- 
2.13.1