From: Mikulas Patocka <mpatocka@xxxxxxxxxx> This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit 4e870e948fbabf62b78e8410f04c67703e7c816b ] 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 <mpatocka@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # v3.16+ Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> --- drivers/md/dm-crypt.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 049282e..b6557bd 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1898,6 +1898,13 @@ static int crypt_map(struct dm_target *ti, struct bio *bio) 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); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html