From c80498a9f6b91d35bc6b6dfd185886d8d4346d43 Mon Sep 17 00:00:00 2001 From: Milan Broz Date: Mon, 14 Apr 2014 22:02:30 +0200 Subject: [PATCH] dm verity: fix biovecs hash calculation regression commit 3a7745215e7f73a5c7d9bcdc50661a55b39052a3 upstream. Commit 003b5c5719f159f4f4bf97511c4702a0638313dd ("block: Convert drivers to immutable biovecs") incorrectly converted biovec iteration in dm-verity to always calculate the hash from a full biovec, but the function only needs to calculate the hash from part of the biovec (up to the calculated "todo" value). Fix this issue by limiting hash input to only the requested data size. This problem was identified using the cryptsetup regression test for veritysetup (verity-compat-test). Signed-off-by: Milan Broz Acked-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-verity.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c index 796007a5e0e1..7a7bab8947ae 100644 --- a/drivers/md/dm-verity.c +++ b/drivers/md/dm-verity.c @@ -330,15 +330,17 @@ test_block_hash: return r; } } - todo = 1 << v->data_dev_block_bits; - while (io->iter.bi_size) { + do { u8 *page; + unsigned len; struct bio_vec bv = bio_iter_iovec(bio, io->iter); page = kmap_atomic(bv.bv_page); - r = crypto_shash_update(desc, page + bv.bv_offset, - bv.bv_len); + len = bv.bv_len; + if (likely(len >= todo)) + len = todo; + r = crypto_shash_update(desc, page + bv.bv_offset, len); kunmap_atomic(page); if (r < 0) { @@ -346,8 +348,9 @@ test_block_hash: return r; } - bio_advance_iter(bio, &io->iter, bv.bv_len); - } + bio_advance_iter(bio, &io->iter, len); + todo -= len; + } while (todo); if (!v->version) { r = crypto_shash_update(desc, v->salt, v->salt_size); -- 2.39.2