From 09c2c359be546df45be0b158ea1d3cc8ea83c876 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 11 Sep 2017 09:46:49 -0600 Subject: 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 Fixes: 615d22a51c04 ("block: Fix __blkdev_issue_zeroout loop") Reviewed-by: Damien Le Moal Signed-off-by: Jens Axboe --- block/blk-lib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'block/blk-lib.c') diff --git a/block/blk-lib.c b/block/blk-lib.c index e01adb5145b3..62240f8832ca 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -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); } /** -- cgit v1.2.3-59-g8ed1b