From 27c7003697fc2c78f965984aa224ef26cd6b2949 Mon Sep 17 00:00:00 2001
From: Milan Broz <gmazyland@gmail.com>
Date: Wed, 3 Jan 2018 22:48:59 +0100
Subject: [PATCH] dm crypt: fix crash by adding missing check for auth key size
Git-commit: 27c7003697fc2c78f965984aa224ef26cd6b2949
Patch-mainline: v4.15-rc9
References: bsc#1093023
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: ef43aa3806 ("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>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm-crypt.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 9fc12f556534..4cc3809b2a3a 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -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],
--
2.16.3