From 5f2808ff1582202175d3908973eb9e05a5e6625d Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Fri, 21 Oct 2016 17:32:24 +0200
Subject: [PATCH] sd: fix uninitialized variable access in error handling
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If sd_zbc_report_zones fails, the check for 'zone_blocks == 0'
later in the function accesses uninitialized data:
drivers/scsi/sd_zbc.c: In function âsd_zbc_read_zonesâ:
drivers/scsi/sd_zbc.c:520:7: error: âzone_blocksâ may be used uninitialized in this function [-Werror=maybe-uninitialized]
This sets it to zero, which has the desired effect of leaving
the sd_zbc_read_zones successfully with sdkp->zone_blocks = 0.
Fixes: 89d947561077 ("sd: Implement support for ZBC devices")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
drivers/scsi/sd_zbc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index 16d3fa62d8acb..d5b3bd915d9eb 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -455,8 +455,10 @@ static int sd_zbc_check_zone_size(struct scsi_disk *sdkp)
/* Do a report zone to get the same field */
ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0);
- if (ret)
+ if (ret) {
+ zone_blocks = 0;
goto out;
+ }
same = buf[4] & 0x0f;
if (same > 0) {
--
2.30.2