From bd4f0fe8bb7c73c738e1e11bc90d6e2cf9c6e20e Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Wed, 23 Feb 2011 00:14:19 -0600 Subject: eCryptfs: Remove unnecessary grow_file() function When creating a new eCryptfs file, the crypto metadata is written out and then the lower file was being "grown" with 4 kB of encrypted zeroes. I suspect that growing the encrypted file was to prevent an information leak that the unencrypted file was empty. However, the unencrypted file size is stored, in plaintext, in the metadata so growing the file is unnecessary. Signed-off-by: Tyler Hicks --- fs/ecryptfs/crypto.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/ecryptfs/crypto.c') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index bfd8b680e648..98a2a314ea68 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1389,6 +1389,7 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) rc = -ENOMEM; goto out; } + /* Zeroed page ensures the in-header unencrypted i_size is set to 0 */ rc = ecryptfs_write_headers_virt(virt, virt_len, &size, crypt_stat, ecryptfs_dentry); if (unlikely(rc)) { -- cgit v1.2.3 From cf35ca69131d5fc8febb74629d173e0731bf49c0 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Mon, 21 Mar 2011 16:00:51 +0100 Subject: eCryptfs: removed num_global_auth_toks from ecryptfs_mount_crypt_stat This patch removes the 'num_global_auth_toks' field of the ecryptfs_mount_crypt_stat structure, used to count the number of items in the 'global_auth_tok_list' list. This variable is not needed because there are no checks based upon it. Signed-off-by: Roberto Sassu Signed-off-by: Tyler Hicks --- fs/ecryptfs/crypto.c | 1 - fs/ecryptfs/ecryptfs_kernel.h | 1 - fs/ecryptfs/keystore.c | 1 - 3 files changed, 3 deletions(-) (limited to 'fs/ecryptfs/crypto.c') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 98a2a314ea68..d2a70a4561f9 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -266,7 +266,6 @@ void ecryptfs_destroy_mount_crypt_stat( &mount_crypt_stat->global_auth_tok_list, mount_crypt_stat_list) { list_del(&auth_tok->mount_crypt_stat_list); - mount_crypt_stat->num_global_auth_toks--; if (auth_tok->global_auth_tok_key && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID)) key_put(auth_tok->global_auth_tok_key); diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index 3ef5b0030231..6c6b8261092e 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -378,7 +378,6 @@ struct ecryptfs_mount_crypt_stat { u32 flags; struct list_head global_auth_tok_list; struct mutex global_auth_tok_list_mutex; - size_t num_global_auth_toks; size_t global_default_cipher_key_size; size_t global_default_fn_cipher_key_bytes; unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index 4feb78c23651..523e51dec66e 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -2454,7 +2454,6 @@ ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); list_add(&new_auth_tok->mount_crypt_stat_list, &mount_crypt_stat->global_auth_tok_list); - mount_crypt_stat->num_global_auth_toks++; mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); out: return rc; -- cgit v1.2.3 From 3aeb86ea4cd15f728147a3bd5469a205ada8c767 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Tue, 15 Mar 2011 14:54:00 -0500 Subject: eCryptfs: Handle failed metadata read in lookup When failing to read the lower file's crypto metadata during a lookup, eCryptfs must continue on without throwing an error. For example, there may be a plaintext file in the lower mount point that the user wants to delete through the eCryptfs mount. If an error is encountered while reading the metadata in lookup(), the eCryptfs inode's size could be incorrect. We must be sure to reread the plaintext inode size from the metadata when performing an open() or setattr(). The metadata is already being read in those paths, so this adds minimal performance overhead. This patch introduces a flag which will track whether or not the plaintext inode size has been read so that an incorrect i_size can be fixed in the open() or setattr() paths. https://bugs.launchpad.net/bugs/509180 Cc: Signed-off-by: Tyler Hicks --- fs/ecryptfs/crypto.c | 21 +++++++++++++++++++++ fs/ecryptfs/ecryptfs_kernel.h | 2 ++ fs/ecryptfs/file.c | 3 ++- fs/ecryptfs/inode.c | 18 +++--------------- 4 files changed, 28 insertions(+), 16 deletions(-) (limited to 'fs/ecryptfs/crypto.c') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index d2a70a4561f9..b8d5c8091024 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1452,6 +1452,25 @@ static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat) crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; } +void ecryptfs_i_size_init(const char *page_virt, struct inode *inode) +{ + struct ecryptfs_mount_crypt_stat *mount_crypt_stat; + struct ecryptfs_crypt_stat *crypt_stat; + u64 file_size; + + crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; + mount_crypt_stat = + &ecryptfs_superblock_to_private(inode->i_sb)->mount_crypt_stat; + if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) { + file_size = i_size_read(ecryptfs_inode_to_lower(inode)); + if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) + file_size += crypt_stat->metadata_size; + } else + file_size = get_unaligned_be64(page_virt); + i_size_write(inode, (loff_t)file_size); + crypt_stat->flags |= ECRYPTFS_I_SIZE_INITIALIZED; +} + /** * ecryptfs_read_headers_virt * @page_virt: The virtual address into which to read the headers @@ -1482,6 +1501,8 @@ static int ecryptfs_read_headers_virt(char *page_virt, rc = -EINVAL; goto out; } + if (!(crypt_stat->flags & ECRYPTFS_I_SIZE_INITIALIZED)) + ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode); offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset), &bytes_read); diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index 380bee1094c3..e70282775e2c 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -269,6 +269,7 @@ struct ecryptfs_crypt_stat { #define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800 #define ECRYPTFS_ENCFN_USE_FEK 0x00001000 #define ECRYPTFS_UNLINK_SIGS 0x00002000 +#define ECRYPTFS_I_SIZE_INITIALIZED 0x00004000 u32 flags; unsigned int file_version; size_t iv_bytes; @@ -628,6 +629,7 @@ struct ecryptfs_open_req { int ecryptfs_interpose(struct dentry *hidden_dentry, struct dentry *this_dentry, struct super_block *sb, u32 flags); +void ecryptfs_i_size_init(const char *page_virt, struct inode *inode); int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, struct dentry *lower_dentry, struct inode *ecryptfs_dir_inode); diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 146c4edff70c..566e5472f78c 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -235,7 +235,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file) goto out_put; } rc = 0; - crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); + crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED + | ECRYPTFS_ENCRYPTED); mutex_unlock(&crypt_stat->cs_mutex); goto out; } diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index f6b388638c3d..2c19d362d2d4 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -225,10 +225,8 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, struct dentry *lower_dir_dentry; struct vfsmount *lower_mnt; struct inode *lower_inode; - struct ecryptfs_mount_crypt_stat *mount_crypt_stat; struct ecryptfs_crypt_stat *crypt_stat; char *page_virt = NULL; - u64 file_size; int put_lower = 0, rc = 0; lower_dir_dentry = lower_dentry->d_parent; @@ -302,18 +300,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, } crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; } - mount_crypt_stat = &ecryptfs_superblock_to_private( - ecryptfs_dentry->d_sb)->mount_crypt_stat; - if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) { - if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) - file_size = (crypt_stat->metadata_size - + i_size_read(lower_dentry->d_inode)); - else - file_size = i_size_read(lower_dentry->d_inode); - } else { - file_size = get_unaligned_be64(page_virt); - } - i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size); + ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode); out_free_kmem: kmem_cache_free(ecryptfs_header_cache_2, page_virt); goto out; @@ -937,7 +924,8 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) goto out; } rc = 0; - crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); + crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED + | ECRYPTFS_ENCRYPTED); } } mutex_unlock(&crypt_stat->cs_mutex); -- cgit v1.2.3