Commit f52236e0 authored May 18, 2017 by Gilad Ben-Yossef Committed by Mike Snitzer May 22, 2017

dm verity: fix no salt use case



DM-Verity has an (undocumented) mode where no salt is used.  This was
never handled directly by the DM-Verity code, instead working due to the
fact that calling crypto_shash_update() with a zero length data is an
implicit noop.

This is no longer the case now that we have switched to
crypto_ahash_update().  Fix the issue by introducing explicit handling
of the no salt use case to DM-Verity.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Reported-by: Marian Csontos <mcsontos@redhat.com>
Fixes: d1ac3ff0 ("dm verity: switch to using asynchronous hash crypto API")
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

parent 08332893

drivers/md/dm-verity-target.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -166,7 +166,7 @@ static int verity_hash_init(struct dm_verity v, struct ahash_request req,
		return r;
		}

		if (likely(v->version >= 1))
		if (likely(v->salt_size && (v->version >= 1)))
		r = verity_hash_update(v, req, v->salt, v->salt_size, res);

		return r;
		@@ -177,7 +177,7 @@ static int verity_hash_final(struct dm_verity v, struct ahash_request req,
		{
		int r;

		if (unlikely(!v->version)) {
		if (unlikely(v->salt_size && (!v->version))) {
		r = verity_hash_update(v, req, v->salt, v->salt_size, res);

		if (r < 0) {