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author | Milan Broz <mbroz@redhat.com> | 2009-12-10 23:51:56 +0000 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-12-18 14:05:01 -0800 |
commit | c22d66f16eaeec0d3c4df607f425f4ebf2b8d238 (patch) | |
tree | 4eaa99a261f16622722604b2d85f682419ab6f30 | |
parent | c7f27e82997f9c835b4c241d1f302501d0cdcc9e (diff) | |
download | lwn-c22d66f16eaeec0d3c4df607f425f4ebf2b8d238.tar.gz lwn-c22d66f16eaeec0d3c4df607f425f4ebf2b8d238.zip |
dm crypt: restructure essiv error path
commit 5861f1be00b3b70f8ab5e5a81392a6cf69666cd2 upstream.
Use kzfree for salt deallocation because it is derived from the volume
key. Use a common error path in ESSIV constructor.
Required by a later patch which fixes the way key material is wiped
from memory.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r-- | drivers/md/dm-crypt.c | 46 |
1 files changed, 26 insertions, 20 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 9fa1b88b9680..2856bdca2515 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -187,15 +187,15 @@ static void crypt_iv_essiv_dtr(struct crypt_config *cc) static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, const char *opts) { - struct crypto_cipher *essiv_tfm; - struct crypto_hash *hash_tfm; + struct crypto_cipher *essiv_tfm = NULL; + struct crypto_hash *hash_tfm = NULL; struct hash_desc desc; struct scatterlist sg; unsigned int saltsize; - u8 *salt; + u8 *salt = NULL; int err; - if (opts == NULL) { + if (!opts) { ti->error = "Digest algorithm missing for ESSIV mode"; return -EINVAL; } @@ -204,15 +204,16 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); if (IS_ERR(hash_tfm)) { ti->error = "Error initializing ESSIV hash"; - return PTR_ERR(hash_tfm); + err = PTR_ERR(hash_tfm); + goto bad; } saltsize = crypto_hash_digestsize(hash_tfm); - salt = kmalloc(saltsize, GFP_KERNEL); - if (salt == NULL) { + salt = kzalloc(saltsize, GFP_KERNEL); + if (!salt) { ti->error = "Error kmallocing salt storage in ESSIV"; - crypto_free_hash(hash_tfm); - return -ENOMEM; + err = -ENOMEM; + goto bad; } sg_init_one(&sg, cc->key, cc->key_size); @@ -220,39 +221,44 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; err = crypto_hash_digest(&desc, &sg, cc->key_size, salt); crypto_free_hash(hash_tfm); + hash_tfm = NULL; if (err) { ti->error = "Error calculating hash in ESSIV"; - kfree(salt); - return err; + goto bad; } /* Setup the essiv_tfm with the given salt */ essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); if (IS_ERR(essiv_tfm)) { ti->error = "Error allocating crypto tfm for ESSIV"; - kfree(salt); - return PTR_ERR(essiv_tfm); + err = PTR_ERR(essiv_tfm); + goto bad; } if (crypto_cipher_blocksize(essiv_tfm) != crypto_ablkcipher_ivsize(cc->tfm)) { ti->error = "Block size of ESSIV cipher does " "not match IV size of block cipher"; - crypto_free_cipher(essiv_tfm); - kfree(salt); - return -EINVAL; + err = -EINVAL; + goto bad; } err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); if (err) { ti->error = "Failed to set key for ESSIV cipher"; - crypto_free_cipher(essiv_tfm); - kfree(salt); - return err; + goto bad; } - kfree(salt); + kzfree(salt); cc->iv_gen_private.essiv.tfm = essiv_tfm; return 0; + +bad: + if (essiv_tfm && !IS_ERR(essiv_tfm)) + crypto_free_cipher(essiv_tfm); + if (hash_tfm && !IS_ERR(hash_tfm)) + crypto_free_hash(hash_tfm); + kzfree(salt); + return err; } static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |