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/inode.c | 23 ----------------------- 1 file changed, 23 deletions(-) (limited to 'fs/ecryptfs/inode.c') diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index b592938a84b..8fa365acb78 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -142,26 +142,6 @@ out: return rc; } -/** - * grow_file - * @ecryptfs_dentry: the eCryptfs dentry - * - * This is the code which will grow the file to its correct size. - */ -static int grow_file(struct dentry *ecryptfs_dentry) -{ - struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; - char zero_virt[] = { 0x00 }; - int rc = 0; - - rc = ecryptfs_write(ecryptfs_inode, zero_virt, 0, 1); - i_size_write(ecryptfs_inode, 0); - rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode); - ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |= - ECRYPTFS_NEW_FILE; - return rc; -} - /** * ecryptfs_initialize_file * @@ -202,9 +182,6 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc); goto out; } - rc = grow_file(ecryptfs_dentry); - if (rc) - printk(KERN_ERR "Error growing file; rc = [%d]\n", rc); out: return rc; } -- cgit v1.2.3-70-g09d2 From fed8859b3ab94274c986cbdf7d27130e0545f02c Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Wed, 23 Feb 2011 00:54:20 -0600 Subject: eCryptfs: Remove ECRYPTFS_NEW_FILE crypt stat flag Now that grow_file() is not called in the ecryptfs_create() path, the ECRYPTFS_NEW_FILE flag is no longer needed. It helped ecryptfs_readpage() know not to decrypt zeroes that were read from the lower file in the grow_file() path. Signed-off-by: Tyler Hicks --- fs/ecryptfs/ecryptfs_kernel.h | 25 ++++++++++++------------- fs/ecryptfs/inode.c | 1 - fs/ecryptfs/mmap.c | 15 ++------------- 3 files changed, 14 insertions(+), 27 deletions(-) (limited to 'fs/ecryptfs/inode.c') diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index e00753496e3..427478e2976 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -257,19 +257,18 @@ struct ecryptfs_filename { struct ecryptfs_crypt_stat { #define ECRYPTFS_STRUCT_INITIALIZED 0x00000001 #define ECRYPTFS_POLICY_APPLIED 0x00000002 -#define ECRYPTFS_NEW_FILE 0x00000004 -#define ECRYPTFS_ENCRYPTED 0x00000008 -#define ECRYPTFS_SECURITY_WARNING 0x00000010 -#define ECRYPTFS_ENABLE_HMAC 0x00000020 -#define ECRYPTFS_ENCRYPT_IV_PAGES 0x00000040 -#define ECRYPTFS_KEY_VALID 0x00000080 -#define ECRYPTFS_METADATA_IN_XATTR 0x00000100 -#define ECRYPTFS_VIEW_AS_ENCRYPTED 0x00000200 -#define ECRYPTFS_KEY_SET 0x00000400 -#define ECRYPTFS_ENCRYPT_FILENAMES 0x00000800 -#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00001000 -#define ECRYPTFS_ENCFN_USE_FEK 0x00002000 -#define ECRYPTFS_UNLINK_SIGS 0x00004000 +#define ECRYPTFS_ENCRYPTED 0x00000004 +#define ECRYPTFS_SECURITY_WARNING 0x00000008 +#define ECRYPTFS_ENABLE_HMAC 0x00000010 +#define ECRYPTFS_ENCRYPT_IV_PAGES 0x00000020 +#define ECRYPTFS_KEY_VALID 0x00000040 +#define ECRYPTFS_METADATA_IN_XATTR 0x00000080 +#define ECRYPTFS_VIEW_AS_ENCRYPTED 0x00000100 +#define ECRYPTFS_KEY_SET 0x00000200 +#define ECRYPTFS_ENCRYPT_FILENAMES 0x00000400 +#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800 +#define ECRYPTFS_ENCFN_USE_FEK 0x00001000 +#define ECRYPTFS_UNLINK_SIGS 0x00002000 u32 flags; unsigned int file_version; size_t iv_bytes; diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 8fa365acb78..f99051b7ada 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -161,7 +161,6 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); goto out; } - crypt_stat->flags |= ECRYPTFS_NEW_FILE; ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n"); rc = ecryptfs_new_file_context(ecryptfs_dentry); if (rc) { diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c index cc64fca89f8..519af27db05 100644 --- a/fs/ecryptfs/mmap.c +++ b/fs/ecryptfs/mmap.c @@ -193,11 +193,7 @@ static int ecryptfs_readpage(struct file *file, struct page *page) &ecryptfs_inode_to_private(page->mapping->host)->crypt_stat; int rc = 0; - if (!crypt_stat - || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED) - || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { - ecryptfs_printk(KERN_DEBUG, - "Passing through unencrypted page\n"); + if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { rc = ecryptfs_read_lower_page_segment(page, page->index, 0, PAGE_CACHE_SIZE, page->mapping->host); @@ -295,8 +291,7 @@ static int ecryptfs_write_begin(struct file *file, struct ecryptfs_crypt_stat *crypt_stat = &ecryptfs_inode_to_private(mapping->host)->crypt_stat; - if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED) - || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { + if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { rc = ecryptfs_read_lower_page_segment( page, index, 0, PAGE_CACHE_SIZE, mapping->host); if (rc) { @@ -487,12 +482,6 @@ static int ecryptfs_write_end(struct file *file, &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; int rc; - if (crypt_stat->flags & ECRYPTFS_NEW_FILE) { - ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in " - "crypt_stat at memory location [%p]\n", crypt_stat); - crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE); - } else - ecryptfs_printk(KERN_DEBUG, "Not a new file\n"); ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" "(page w/ index = [0x%.16lx], to = [%d])\n", index, to); if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { -- cgit v1.2.3-70-g09d2