[PATCH 3.10 016/268] dm crypt: mark key as invalid until properly loaded

Willy Tarreau
2017-06-19T19:23:12Z

From: Ondrej Kozina <okozina@redhat.com>

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: Willy Tarreau <w@1wt.eu>
---
drivers/md/dm-crypt.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 7409d79..53ce281 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1283,12 +1283,15 @@ 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. */
--
2.8.0.rc2.1.gbe9624a