Commit e81f3340 authored by Herbert Xu's avatar Herbert Xu
Browse files

eCryptfs: Do not allocate hash tfm in NORECLAIM context 



You cannot allocate crypto tfm objects in NORECLAIM or NOFS contexts.
The ecryptfs code currently does exactly that for the MD5 tfm.

This patch fixes it by preallocating the MD5 tfm in a safe context.

The MD5 tfm is also reentrant so this patch removes the superfluous
cs_hash_tfm_mutex.

Reported-by: default avatarNicolas Boichat <drinkcat@chromium.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent b3ab30a7

fs/ecryptfs/crypto.c

+16 −16
Original line number Original line Diff line number Diff line
@@ -105,19 +105,7 @@ static int ecryptfs_calculate_md5(char *dst, 
	struct crypto_shash *tfm;

	struct crypto_shash *tfm;

	int rc = 0;

	int rc = 0;





	mutex_lock(&crypt_stat->cs_hash_tfm_mutex);

	tfm = crypt_stat->hash_tfm;

	tfm = crypt_stat->hash_tfm;

	if (!tfm) {

		tfm = crypto_alloc_shash(ECRYPTFS_DEFAULT_HASH, 0, 0);

		if (IS_ERR(tfm)) {

			rc = PTR_ERR(tfm);

			ecryptfs_printk(KERN_ERR, "Error attempting to "

					"allocate crypto context; rc = [%d]\n",

					rc);

			goto out;

		}

		crypt_stat->hash_tfm = tfm;

	}

	rc = ecryptfs_hash_digest(tfm, src, len, dst);

	rc = ecryptfs_hash_digest(tfm, src, len, dst);

	if (rc) {

	if (rc) {

		printk(KERN_ERR

		printk(KERN_ERR
@@ -126,7 +114,6 @@ static int ecryptfs_calculate_md5(char *dst, 
		goto out;

		goto out;

	}

	}

out:

out:

	mutex_unlock(&crypt_stat->cs_hash_tfm_mutex);

	return rc;

	return rc;

}

}
@@ -207,16 +194,29 @@ out: 
 *

 *

 * Initialize the crypt_stat structure.

 * Initialize the crypt_stat structure.

 */

 */

void

int ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat)

ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat)

{

{

	struct crypto_shash *tfm;

	int rc;



	tfm = crypto_alloc_shash(ECRYPTFS_DEFAULT_HASH, 0, 0);

	if (IS_ERR(tfm)) {

		rc = PTR_ERR(tfm);

		ecryptfs_printk(KERN_ERR, "Error attempting to "

				"allocate crypto context; rc = [%d]\n",

				rc);

		return rc;

	}



	memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat));

	memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat));

	INIT_LIST_HEAD(&crypt_stat->keysig_list);

	INIT_LIST_HEAD(&crypt_stat->keysig_list);

	mutex_init(&crypt_stat->keysig_list_mutex);

	mutex_init(&crypt_stat->keysig_list_mutex);

	mutex_init(&crypt_stat->cs_mutex);

	mutex_init(&crypt_stat->cs_mutex);

	mutex_init(&crypt_stat->cs_tfm_mutex);

	mutex_init(&crypt_stat->cs_tfm_mutex);

	mutex_init(&crypt_stat->cs_hash_tfm_mutex);

	crypt_stat->hash_tfm = tfm;

	crypt_stat->flags |= ECRYPTFS_STRUCT_INITIALIZED;

	crypt_stat->flags |= ECRYPTFS_STRUCT_INITIALIZED;



	return 0;

}

}





/**

/**

fs/ecryptfs/ecryptfs_kernel.h

+1 −2
Original line number Original line Diff line number Diff line
@@ -242,7 +242,6 @@ struct ecryptfs_crypt_stat { 
	struct list_head keysig_list;

	struct list_head keysig_list;

	struct mutex keysig_list_mutex;

	struct mutex keysig_list_mutex;

	struct mutex cs_tfm_mutex;

	struct mutex cs_tfm_mutex;

	struct mutex cs_hash_tfm_mutex;

	struct mutex cs_mutex;

	struct mutex cs_mutex;

};

};
@@ -577,7 +576,7 @@ int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, 
			int sg_size);

			int sg_size);

int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat);

int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat);

void ecryptfs_rotate_iv(unsigned char *iv);

void ecryptfs_rotate_iv(unsigned char *iv);

void ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);

int ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);

void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);

void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);

void ecryptfs_destroy_mount_crypt_stat(

void ecryptfs_destroy_mount_crypt_stat(

	struct ecryptfs_mount_crypt_stat *mount_crypt_stat);

	struct ecryptfs_mount_crypt_stat *mount_crypt_stat);

fs/ecryptfs/inode.c

+5 −2
Original line number Original line Diff line number Diff line
@@ -898,8 +898,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) 
	struct ecryptfs_crypt_stat *crypt_stat;

	struct ecryptfs_crypt_stat *crypt_stat;





	crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;

	crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;

	if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))

	if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {

		ecryptfs_init_crypt_stat(crypt_stat);

		rc = ecryptfs_init_crypt_stat(crypt_stat);

		if (rc)

			return rc;

	}

	inode = d_inode(dentry);

	inode = d_inode(dentry);

	lower_inode = ecryptfs_inode_to_lower(inode);

	lower_inode = ecryptfs_inode_to_lower(inode);

	lower_dentry = ecryptfs_dentry_to_lower(dentry);

	lower_dentry = ecryptfs_dentry_to_lower(dentry);

fs/ecryptfs/super.c

+4 −1
Original line number Original line Diff line number Diff line
@@ -55,7 +55,10 @@ static struct inode *ecryptfs_alloc_inode(struct super_block *sb) 
	inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);

	inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);

	if (unlikely(!inode_info))

	if (unlikely(!inode_info))

		goto out;

		goto out;

	ecryptfs_init_crypt_stat(&inode_info->crypt_stat);

	if (ecryptfs_init_crypt_stat(&inode_info->crypt_stat)) {

		kmem_cache_free(ecryptfs_inode_info_cache, inode_info);

		goto out;

	}

	mutex_init(&inode_info->lower_file_mutex);

	mutex_init(&inode_info->lower_file_mutex);

	atomic_set(&inode_info->lower_file_count, 0);

	atomic_set(&inode_info->lower_file_count, 0);

	inode_info->lower_file = NULL;

	inode_info->lower_file = NULL;

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