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: d1ac3ff ("dm verity: switch to using asynchronous hash crypto API")
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Gilad Ben-Yossef 2017-05-18 13:47:25 +03:00 committed by Mike Snitzer
parent 08332893e3
commit f52236e0b0
1 changed files with 2 additions and 2 deletions

View File

@ -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) {