Re: [PATCH] scsi: sd_zbc: Support disks with more than 2**32 logical blocks

On Sep 17, 2021, at 4:23 PM, Bart Van Assche [off-list ref] wrote:

This patch addresses the following Coverity report about the
zno * sdkp->zone_blocks expression:

CID 1475514 (#1 of 1): Unintentional integer overflow (OVERFLOW_BEFORE_WIDEN)
overflow_before_widen: Potentially overflowing expression zno *
sdkp->zone_blocks with type unsigned int (32 bits, unsigned) is evaluated
using 32-bit arithmetic, and then used in a context that expects an
expression of type sector_t (64 bits, unsigned).

Cc: Johannes Thumshirn <redacted>
Cc: Damien Le Moal <redacted>
Cc: Hannes Reinecke <hare@suse.de>
Fixes: 5795eb443060 ("scsi: sd_zbc: emulate ZONE_APPEND commands")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/scsi/sd_zbc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index b9757f24b0d6..ded4d7a070a0 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c

@@ -280,7 +280,7 @@ static void sd_zbc_update_wp_offset_workfn(struct work_struct *work)

{
	struct scsi_disk *sdkp;
	unsigned long flags;
-	unsigned int zno;
+	sector_t zno;
	int ret;

	sdkp = container_of(work, struct scsi_disk, zone_wp_offset_work);