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: 615d22a51c04 ("block: Fix __blkdev_issue_zeroout loop")
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-lib.c b/block/blk-lib.c
index e01adb5..62240f8 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -269,9 +269,9 @@
*/
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);
}
/**