block: fix integer overflow in __blkdev_sectors_to_bio_pages()

Fix possible integer overflow in __blkdev_sectors_to_bio_pages if
sector_t is 32-bit.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 615d22a51c ("block: Fix __blkdev_issue_zeroout loop")
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Mikulas Patocka 2017-09-11 09:46:49 -06:00 committed by Jens Axboe
parent dbec491b12
commit 09c2c359be

View File

@ -269,9 +269,9 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev,
*/
static unsigned int __blkdev_sectors_to_bio_pages(sector_t nr_sects)
{
sector_t bytes = (nr_sects << 9) + PAGE_SIZE - 1;
sector_t pages = DIV_ROUND_UP_SECTOR_T(nr_sects, PAGE_SIZE / 512);
return min(bytes >> PAGE_SHIFT, (sector_t)BIO_MAX_PAGES);
return min(pages, (sector_t)BIO_MAX_PAGES);
}
/**