Path: csiph.com!news.mixmin.net!aioe.org!bofh.it!news.nic.it!robomod From: Greg Kroah-Hartman Newsgroups: linux.kernel Subject: [PATCH 4.4 063/118] dm crypt: fix error with too large bios Date: Thu, 22 Sep 2016 19:40:01 +0200 Message-ID: References: X-Mailer: git-send-email 2.10.0 User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 43 Organization: linux.* mail to news gateway X-Original-Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Mike Snitzer X-Original-Date: Thu, 22 Sep 2016 19:29:23 +0200 X-Original-Message-ID: <20160922172941.907107540@linuxfoundation.org> X-Original-References: <20160922172938.643879685@linuxfoundation.org> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1489118 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit 4e870e948fbabf62b78e8410f04c67703e7c816b upstream. When dm-crypt processes writes, it allocates a new bio in crypt_alloc_buffer(). The bio is allocated from a bio set and it can have at most BIO_MAX_PAGES vector entries, however the incoming bio can be larger (e.g. if it was allocated by bcache). If the incoming bio is larger, bio_alloc_bioset() fails and an error is returned. To avoid the error, we test for a too large bio in the function crypt_map() and use dm_accept_partial_bio() to split the bio. dm_accept_partial_bio() trims the current bio to the desired size and asks DM core to send another bio with the rest of the data. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-crypt.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1920,6 +1920,13 @@ static int crypt_map(struct dm_target *t return DM_MAPIO_REMAPPED; } + /* + * Check if bio is too large, split as needed. + */ + if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) && + bio_data_dir(bio) == WRITE) + dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT)); + io = dm_per_bio_data(bio, cc->per_bio_data_size); crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); io->ctx.req = (struct ablkcipher_request *)(io + 1);