block: Limit allocation of zone descriptors for report zones

There is no point in allocating more zone descriptors than the number of zones a block device has for doing a zone report. Avoid doing that in blkdev_report_zones_ioctl() by limiting the number of zone decriptors allocated internally to process the user request. Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Signed-off-by: Damien Le Moal <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
chewitt · Oct 25, 2018 · 2e85fba · 2e85fba
1 parent a91e138
commit 2e85fba
Showing 1 changed file with 1 addition and 2 deletions.
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
@@ -355,8 +355,7 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
 	if (!rep.nr_zones)
 		return -EINVAL;
 
-	if (rep.nr_zones > INT_MAX / sizeof(struct blk_zone))
-		return -ERANGE;
+	rep.nr_zones = min(blkdev_nr_zones(bdev), rep.nr_zones);
 
 	zones = kvmalloc_array(rep.nr_zones, sizeof(struct blk_zone),
 			       GFP_KERNEL | __GFP_ZERO);