Commit 27c70036 authored Jan 03, 2018 by Milan Broz Committed by Mike Snitzer Jan 17, 2018

dm crypt: fix crash by adding missing check for auth key size



If dm-crypt uses authenticated mode with separate MAC, there are two
concatenated part of the key structure - key(s) for encryption and
authentication key.

Add a missing check for authenticated key length.  If this key length is
smaller than actually provided key, dm-crypt now properly fails instead
of crashing.

Fixes: ef43aa38 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)")
Cc: stable@vger.kernel.org # 4.12+
Reported-by: Salah Coronya <salahx@yahoo.com>
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

parent bc68d0a4

drivers/md/dm-crypt.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1954,10 +1954,15 @@ static int crypt_setkey(struct crypt_config *cc)
		/* Ignore extra keys (which are used for IV etc) */
		subkey_size = crypt_subkey_size(cc);

		if (crypt_integrity_hmac(cc))
		if (crypt_integrity_hmac(cc)) {
		if (subkey_size < cc->key_mac_size)
		return -EINVAL;

		crypt_copy_authenckey(cc->authenc_key, cc->key,
		subkey_size - cc->key_mac_size,
		cc->key_mac_size);
		}

		for (i = 0; i < cc->tfms_count; i++) {
		if (crypt_integrity_hmac(cc))
		r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],