scsi: sd_zbc: Reject disks with too many zones

sd_zbc_read_zones() computes the number of zones with 64-bit arithmetic and
stores the result in the unsigned int nr_zones field of struct
zoned_disk_info, silently truncating counts that exceed 32 bits. The
truncated count is later used to size per-zone resources, while the device
may still report more zones than fit.

Moreover, sd_zbc_report_zones() counts the reported zones with a signed int
zone_idx, which overflows past INT_MAX. Reject devices reporting more than
INT_MAX zones at scan time; such a device is not realistic for any medium
that exists today, and accepting it produces inconsistent zone bookkeeping.

Fixes: 89d9475610 ("sd: Implement support for ZBC devices")
Signed-off-by: ZHOU Jiaxiang <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Martin K. Petersen (Oracle) <[email protected]>

drivers/scsi/sd_zbc.c

@@ -589,7 +589,7 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
 int sd_zbc_read_zones(struct scsi_disk *sdkp, struct queue_limits *lim,
 		u8 buf[SD_BUF_SIZE])
 {
-	unsigned int nr_zones;
+	u64 nr_zones;
 	u32 zone_blocks = 0;
 	int ret;
 
@@ -621,6 +621,12 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, struct queue_limits *lim,
 		goto err;
 
 	nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
+	if (nr_zones > INT_MAX) {
+		sd_printk(KERN_ERR, sdkp, "Too many zones (%llu)\n",
+			  nr_zones);
+		ret = -EINVAL;
+		goto err;
+	}
 	sdkp->early_zone_info.nr_zones = nr_zones;
 	sdkp->early_zone_info.zone_blocks = zone_blocks;