From: Christoph Hellwig <hch@xxxxxx> [ Upstream commit 73a768d5f95533574bb8ace34eb683a88c40509e ] Contrary to the comment in __blkdev_issue_write_zeroes, nothing here checks for a potential bi_size overflow. Add a helper mirroring the secure erase code for the check. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240701165219.1571322-6-hch@xxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- block/blk-lib.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index 442da9dad0421..297bcf6896930 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -103,24 +103,28 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, } EXPORT_SYMBOL(blkdev_issue_discard); +static sector_t bio_write_zeroes_limit(struct block_device *bdev) +{ + sector_t bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; + + return min(bdev_write_zeroes_sectors(bdev), + (UINT_MAX >> SECTOR_SHIFT) & ~bs_mask); +} + static int __blkdev_issue_write_zeroes(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop, unsigned flags) { struct bio *bio = *biop; - unsigned int max_sectors; if (bdev_read_only(bdev)) return -EPERM; - - /* Ensure that max_sectors doesn't overflow bi_size */ - max_sectors = bdev_write_zeroes_sectors(bdev); - - if (max_sectors == 0) + if (!bdev_write_zeroes_sectors(bdev)) return -EOPNOTSUPP; while (nr_sects) { - unsigned int len = min_t(sector_t, nr_sects, max_sectors); + unsigned int len = min_t(sector_t, nr_sects, + bio_write_zeroes_limit(bdev)); bio = blk_next_bio(bio, bdev, 0, REQ_OP_WRITE_ZEROES, gfp_mask); bio->bi_iter.bi_sector = sector; -- 2.43.0
