Commit 5861f1be00b3b70f8ab5e5a81392a6cf69666cd2
Committed by
Alasdair G Kergon
1 parent
6047359277
Exists in
master
and in
7 other branches
dm crypt: restructure essiv error path
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. Cc: stable@kernel.org Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Showing 1 changed file with 26 additions and 20 deletions Side-by-side Diff
drivers/md/dm-crypt.c
... | ... | @@ -187,15 +187,15 @@ |
187 | 187 | static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, |
188 | 188 | const char *opts) |
189 | 189 | { |
190 | - struct crypto_cipher *essiv_tfm; | |
191 | - struct crypto_hash *hash_tfm; | |
190 | + struct crypto_cipher *essiv_tfm = NULL; | |
191 | + struct crypto_hash *hash_tfm = NULL; | |
192 | 192 | struct hash_desc desc; |
193 | 193 | struct scatterlist sg; |
194 | 194 | unsigned int saltsize; |
195 | - u8 *salt; | |
195 | + u8 *salt = NULL; | |
196 | 196 | int err; |
197 | 197 | |
198 | - if (opts == NULL) { | |
198 | + if (!opts) { | |
199 | 199 | ti->error = "Digest algorithm missing for ESSIV mode"; |
200 | 200 | return -EINVAL; |
201 | 201 | } |
202 | 202 | |
203 | 203 | |
... | ... | @@ -204,15 +204,16 @@ |
204 | 204 | hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); |
205 | 205 | if (IS_ERR(hash_tfm)) { |
206 | 206 | ti->error = "Error initializing ESSIV hash"; |
207 | - return PTR_ERR(hash_tfm); | |
207 | + err = PTR_ERR(hash_tfm); | |
208 | + goto bad; | |
208 | 209 | } |
209 | 210 | |
210 | 211 | saltsize = crypto_hash_digestsize(hash_tfm); |
211 | - salt = kmalloc(saltsize, GFP_KERNEL); | |
212 | - if (salt == NULL) { | |
212 | + salt = kzalloc(saltsize, GFP_KERNEL); | |
213 | + if (!salt) { | |
213 | 214 | ti->error = "Error kmallocing salt storage in ESSIV"; |
214 | - crypto_free_hash(hash_tfm); | |
215 | - return -ENOMEM; | |
215 | + err = -ENOMEM; | |
216 | + goto bad; | |
216 | 217 | } |
217 | 218 | |
218 | 219 | sg_init_one(&sg, cc->key, cc->key_size); |
219 | 220 | |
220 | 221 | |
221 | 222 | |
222 | 223 | |
223 | 224 | |
224 | 225 | |
... | ... | @@ -220,39 +221,44 @@ |
220 | 221 | desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
221 | 222 | err = crypto_hash_digest(&desc, &sg, cc->key_size, salt); |
222 | 223 | crypto_free_hash(hash_tfm); |
224 | + hash_tfm = NULL; | |
223 | 225 | |
224 | 226 | if (err) { |
225 | 227 | ti->error = "Error calculating hash in ESSIV"; |
226 | - kfree(salt); | |
227 | - return err; | |
228 | + goto bad; | |
228 | 229 | } |
229 | 230 | |
230 | 231 | /* Setup the essiv_tfm with the given salt */ |
231 | 232 | essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); |
232 | 233 | if (IS_ERR(essiv_tfm)) { |
233 | 234 | ti->error = "Error allocating crypto tfm for ESSIV"; |
234 | - kfree(salt); | |
235 | - return PTR_ERR(essiv_tfm); | |
235 | + err = PTR_ERR(essiv_tfm); | |
236 | + goto bad; | |
236 | 237 | } |
237 | 238 | if (crypto_cipher_blocksize(essiv_tfm) != |
238 | 239 | crypto_ablkcipher_ivsize(cc->tfm)) { |
239 | 240 | ti->error = "Block size of ESSIV cipher does " |
240 | 241 | "not match IV size of block cipher"; |
241 | - crypto_free_cipher(essiv_tfm); | |
242 | - kfree(salt); | |
243 | - return -EINVAL; | |
242 | + err = -EINVAL; | |
243 | + goto bad; | |
244 | 244 | } |
245 | 245 | err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); |
246 | 246 | if (err) { |
247 | 247 | ti->error = "Failed to set key for ESSIV cipher"; |
248 | - crypto_free_cipher(essiv_tfm); | |
249 | - kfree(salt); | |
250 | - return err; | |
248 | + goto bad; | |
251 | 249 | } |
252 | - kfree(salt); | |
250 | + kzfree(salt); | |
253 | 251 | |
254 | 252 | cc->iv_gen_private.essiv.tfm = essiv_tfm; |
255 | 253 | return 0; |
254 | + | |
255 | +bad: | |
256 | + if (essiv_tfm && !IS_ERR(essiv_tfm)) | |
257 | + crypto_free_cipher(essiv_tfm); | |
258 | + if (hash_tfm && !IS_ERR(hash_tfm)) | |
259 | + crypto_free_hash(hash_tfm); | |
260 | + kzfree(salt); | |
261 | + return err; | |
256 | 262 | } |
257 | 263 | |
258 | 264 | static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |