dm crypt: mark key as invalid until properly loaded

commit 265e9098bac02bc5e36cda21fdbad34cb5b2f48d upstream.

In crypt_set_key(), if a failure occurs while replacing the old key
(e.g. tfm->setkey() fails) the key must not have DM_CRYPT_KEY_VALID flag
set.  Otherwise, the crypto layer would have an invalid key that still
has DM_CRYPT_KEY_VALID flag set.

Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index a2768835d394..0aedd0ebccec 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1503,12 +1503,15 @@ static int crypt_set_key(struct crypt_config *cc, char *key)
         if (!cc->key_size && strcmp(key, "-"))
                 goto out;
 
+        /* clear the flag since following operations may invalidate previously valid key */
+        clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
+
         if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
                 goto out;
 
-        set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
-
         r = crypt_setkey_allcpus(cc);
+        if (!r)
+                set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
 out:
         /* Hex key string not needed after here, so wipe it. */