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Commit 950983fc authored by Roberto Sassu's avatar Roberto Sassu Committed by Tyler Hicks
Browse files

eCryptfs: move ecryptfs_find_auth_tok_for_sig() call before mutex_lock 



The ecryptfs_find_auth_tok_for_sig() call is moved before the
mutex_lock(s->tfm_mutex) instruction in order to avoid possible deadlocks
that may occur by holding the lock on the two semaphores 'key->sem' and
's->tfm_mutex' in reverse order.

Signed-off-by: default avatarRoberto Sassu <roberto.sassu@polito.it>
Signed-off-by: default avatarTyler Hicks <tyhicks@linux.vnet.ibm.com>
parent 0e1fc5ef

fs/ecryptfs/keystore.c

+19 −19
Original line number Diff line number Diff line
@@ -635,6 +635,16 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, 
	}

	s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	(*packet_size) = 0;

	rc = ecryptfs_find_auth_tok_for_sig(

		&auth_tok_key,

		&s->auth_tok, mount_crypt_stat,

		mount_crypt_stat->global_default_fnek_sig);

	if (rc) {

		printk(KERN_ERR "%s: Error attempting to find auth tok for "

		       "fnek sig [%s]; rc = [%d]\n", __func__,

		       mount_crypt_stat->global_default_fnek_sig, rc);

		goto out;

	}

	rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(

		&s->desc.tfm,

		&s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
@@ -720,16 +730,6 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, 
		goto out_free_unlock;

	}

	dest[s->i++] = s->cipher_code;

	rc = ecryptfs_find_auth_tok_for_sig(

		&auth_tok_key,

		&s->auth_tok, mount_crypt_stat,

		mount_crypt_stat->global_default_fnek_sig);

	if (rc) {

		printk(KERN_ERR "%s: Error attempting to find auth tok for "

		       "fnek sig [%s]; rc = [%d]\n", __func__,

		       mount_crypt_stat->global_default_fnek_sig, rc);

		goto out_free_unlock;

	}

	/* TODO: Support other key modules than passphrase for

	 * filename encryption */

	if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
@@ -983,6 +983,15 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, 
		       __func__, s->cipher_code);

		goto out;

	}

	rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key,

					    &s->auth_tok, mount_crypt_stat,

					    s->fnek_sig_hex);

	if (rc) {

		printk(KERN_ERR "%s: Error attempting to find auth tok for "

		       "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,

		       rc);

		goto out;

	}

	rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,

							&s->tfm_mutex,

							s->cipher_string);
@@ -1029,15 +1038,6 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, 
	 * >= ECRYPTFS_MAX_IV_BYTES. */

	memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);

	s->desc.info = s->iv;

	rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key,

					    &s->auth_tok, mount_crypt_stat,

					    s->fnek_sig_hex);

	if (rc) {

		printk(KERN_ERR "%s: Error attempting to find auth tok for "

		       "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,

		       rc);

		goto out_free_unlock;

	}

	/* TODO: Support other key modules than passphrase for

	 * filename encryption */

	if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {