dm crypt: wipe keys string immediately after key is set
Always wipe the original copy of the key after processing it
in crypt_set_key().
Signed-off-by: Milan Broz <mbroz@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 4e054bd..7dcae0d 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1331,20 +1331,29 @@
static int crypt_set_key(struct crypt_config *cc, char *key)
{
+ int r = -EINVAL;
+ int key_string_len = strlen(key);
+
/* The key size may not be changed. */
- if (cc->key_size != (strlen(key) >> 1))
- return -EINVAL;
+ if (cc->key_size != (key_string_len >> 1))
+ goto out;
/* Hyphen (which gives a key_size of zero) means there is no key. */
if (!cc->key_size && strcmp(key, "-"))
- return -EINVAL;
+ goto out;
if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
- return -EINVAL;
+ goto out;
set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
- return crypt_setkey_allcpus(cc);
+ r = crypt_setkey_allcpus(cc);
+
+out:
+ /* Hex key string not needed after here, so wipe it. */
+ memset(key, '0', key_string_len);
+
+ return r;
}
static int crypt_wipe_key(struct crypt_config *cc)