block: Fix potential overflow in blk_report_zones() (113ab72e) · Commits · 戴 / test

For large values of the number of zones reported and/or large zone sizes, the sector increment calculated with blk_queue_zone_sectors(q) * n in blk_report_zones() loop can overflow the unsigned int type used for the calculation as both "n" and blk_queue_zone_sectors() value are unsigned int. E.g. for a device with 256 MB zones (524288 sectors), overflow happens with 8192 or more zones reported. Changing the return type of blk_queue_zone_sectors() to sector_t, fixes this problem and avoids overflow problem for all other callers of this helper too. The same change is also applied to the bdev_zone_sectors() helper. Fixes: ("block: add a report_zones method") Cc: stable@vger.kernel.org Signed-off-by:

Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

block/blk-zoned.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -70,7 +70,7 @@ EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);
		static inline unsigned int __blkdev_nr_zones(struct request_queue *q,
		sector_t nr_sectors)
		{
		unsigned long zone_sectors = blk_queue_zone_sectors(q);
		sector_t zone_sectors = blk_queue_zone_sectors(q);

		return (nr_sectors + zone_sectors - 1) >> ilog2(zone_sectors);
		}

include/linux/blkdev.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -681,7 +681,7 @@ static inline bool blk_queue_is_zoned(struct request_queue *q)
		}
		}

		static inline unsigned int blk_queue_zone_sectors(struct request_queue *q)
		static inline sector_t blk_queue_zone_sectors(struct request_queue *q)
		{
		return blk_queue_is_zoned(q) ? q->limits.chunk_sectors : 0;
		}
		@@ -1418,7 +1418,7 @@ static inline bool bdev_is_zoned(struct block_device *bdev)
		return false;
		}

		static inline unsigned int bdev_zone_sectors(struct block_device *bdev)
		static inline sector_t bdev_zone_sectors(struct block_device *bdev)
		{
		struct request_queue *q = bdev_get_queue(bdev);

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