From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Milan Broz , Mikulas Patocka , Mike Snitzer Subject: [PATCH 3.14 053/228] dm verity: fix biovecs hash calculation regression Date: Wed, 4 Jun 2014 16:21:22 -0700 Message-Id: <20140604232349.775441906@linuxfoundation.org> In-Reply-To: <20140604232347.966798903@linuxfoundation.org> References: <20140604232347.966798903@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Milan Broz 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(-) --- 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);