From: Hou Tao <[email protected]> Both kcryptd_io_read() and kcryptd_crypt_write_convert() will invoke crypt_alloc_buffer() to allocate a new bio. Both of these two callers initialize bi_iter.bi_sector for the new bio separatedly after crypt_alloc_buffer() returns. However, kcryptd_crypt_write_convert() will copy the bi_iter of the new bio into ctx.iter_out or ctx.iter_in. Although it doesn't incur any harm now, it is better to fully initialize bi_iter before it is used.
Therefore, initialize bi_iter.bi_sector in crypt_alloc_buffer() instead. Signed-off-by: Hou Tao <[email protected]> --- drivers/md/dm-crypt.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 424c8fc3f0ada..551c934bfc501 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1719,6 +1719,7 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned int size) clone->bi_private = io; clone->bi_end_io = crypt_endio; clone->bi_ioprio = io->base_bio->bi_ioprio; + clone->bi_iter.bi_sector = cc->start + io->sector; remaining_size = size; @@ -1909,7 +1910,6 @@ static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) crypt_dec_pending(io); return 1; } - clone->bi_iter.bi_sector = cc->start + io->sector; crypt_convert_init(cc, &io->ctx, clone, clone, io->sector); io->saved_bi_iter = clone->bi_iter; dm_submit_bio_remap(io->base_bio, clone); @@ -1925,13 +1925,13 @@ static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs); if (!clone) return 1; + + clone->bi_iter.bi_sector = cc->start + io->sector; clone->bi_private = io; clone->bi_end_io = crypt_endio; crypt_inc_pending(io); - clone->bi_iter.bi_sector = cc->start + io->sector; - if (dm_crypt_integrity_io_alloc(io, clone)) { crypt_dec_pending(io); bio_put(clone); @@ -2039,8 +2039,6 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) /* crypt_convert should have filled the clone bio */ BUG_ON(io->ctx.iter_out.bi_size); - clone->bi_iter.bi_sector = cc->start + io->sector; - if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) || test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) { dm_submit_bio_remap(io->base_bio, clone); -- 2.29.2
