eCryptfs: Handle failed metadata read in lookup
[linux-flexiantxendom0-natty.git] / fs / ecryptfs / crypto.c
index bae20ad..97b0a86 100644 (file)
@@ -33,6 +33,7 @@
 #include <linux/crypto.h>
 #include <linux/file.h>
 #include <linux/scatterlist.h>
+#include <linux/slab.h>
 #include <asm/unaligned.h>
 #include "ecryptfs_kernel.h"
 
@@ -347,7 +348,7 @@ static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
        BUG_ON(!crypt_stat || !crypt_stat->tfm
               || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED));
        if (unlikely(ecryptfs_verbosity > 0)) {
-               ecryptfs_printk(KERN_DEBUG, "Key size [%d]; key:\n",
+               ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n",
                                crypt_stat->key_size);
                ecryptfs_dump_hex(crypt_stat->key,
                                  crypt_stat->key_size);
@@ -381,8 +382,8 @@ out:
 static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
                                             struct ecryptfs_crypt_stat *crypt_stat)
 {
-       (*offset) = (crypt_stat->num_header_bytes_at_front
-                    + (crypt_stat->extent_size * extent_num));
+       (*offset) = ecryptfs_lower_header_size(crypt_stat)
+                   + (crypt_stat->extent_size * extent_num);
 }
 
 /**
@@ -412,10 +413,9 @@ static int ecryptfs_encrypt_extent(struct page *enc_extent_page,
        rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
                                (extent_base + extent_offset));
        if (rc) {
-               ecryptfs_printk(KERN_ERR, "Error attempting to "
-                               "derive IV for extent [0x%.16x]; "
-                               "rc = [%d]\n", (extent_base + extent_offset),
-                               rc);
+               ecryptfs_printk(KERN_ERR, "Error attempting to derive IV for "
+                       "extent [0x%.16llx]; rc = [%d]\n",
+                       (unsigned long long)(extent_base + extent_offset), rc);
                goto out;
        }
        if (unlikely(ecryptfs_verbosity > 0)) {
@@ -442,9 +442,9 @@ static int ecryptfs_encrypt_extent(struct page *enc_extent_page,
        }
        rc = 0;
        if (unlikely(ecryptfs_verbosity > 0)) {
-               ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; "
-                               "rc = [%d]\n", (extent_base + extent_offset),
-                               rc);
+               ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16llx]; "
+                       "rc = [%d]\n",
+                       (unsigned long long)(extent_base + extent_offset), rc);
                ecryptfs_printk(KERN_DEBUG, "First 8 bytes after "
                                "encryption:\n");
                ecryptfs_dump_hex((char *)(page_address(enc_extent_page)), 8);
@@ -509,13 +509,14 @@ int ecryptfs_encrypt_page(struct page *page)
                                  + extent_offset), crypt_stat);
                rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt,
                                          offset, crypt_stat->extent_size);
-               if (rc) {
+               if (rc < 0) {
                        ecryptfs_printk(KERN_ERR, "Error attempting "
                                        "to write lower page; rc = [%d]"
                                        "\n", rc);
                        goto out;
                }
        }
+       rc = 0;
 out:
        if (enc_extent_page) {
                kunmap(enc_extent_page);
@@ -538,10 +539,9 @@ static int ecryptfs_decrypt_extent(struct page *page,
        rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
                                (extent_base + extent_offset));
        if (rc) {
-               ecryptfs_printk(KERN_ERR, "Error attempting to "
-                               "derive IV for extent [0x%.16x]; "
-                               "rc = [%d]\n", (extent_base + extent_offset),
-                               rc);
+               ecryptfs_printk(KERN_ERR, "Error attempting to derive IV for "
+                       "extent [0x%.16llx]; rc = [%d]\n",
+                       (unsigned long long)(extent_base + extent_offset), rc);
                goto out;
        }
        if (unlikely(ecryptfs_verbosity > 0)) {
@@ -569,9 +569,9 @@ static int ecryptfs_decrypt_extent(struct page *page,
        }
        rc = 0;
        if (unlikely(ecryptfs_verbosity > 0)) {
-               ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16x]; "
-                               "rc = [%d]\n", (extent_base + extent_offset),
-                               rc);
+               ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16llx]; "
+                       "rc = [%d]\n",
+                       (unsigned long long)(extent_base + extent_offset), rc);
                ecryptfs_printk(KERN_DEBUG, "First 8 bytes after "
                                "decryption:\n");
                ecryptfs_dump_hex((char *)(page_address(page)
@@ -631,7 +631,7 @@ int ecryptfs_decrypt_page(struct page *page)
                rc = ecryptfs_read_lower(enc_extent_virt, offset,
                                         crypt_stat->extent_size,
                                         ecryptfs_inode);
-               if (rc) {
+               if (rc < 0) {
                        ecryptfs_printk(KERN_ERR, "Error attempting "
                                        "to read lower page; rc = [%d]"
                                        "\n", rc);
@@ -760,7 +760,7 @@ ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,
 
 /**
  * ecryptfs_init_crypt_ctx
- * @crypt_stat: Uninitilized crypt stats structure
+ * @crypt_stat: Uninitialized crypt stats structure
  *
  * Initialize the crypto context.
  *
@@ -778,7 +778,7 @@ int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat)
        }
        ecryptfs_printk(KERN_DEBUG,
                        "Initializing cipher [%s]; strlen = [%d]; "
-                       "key_size_bits = [%d]\n",
+                       "key_size_bits = [%zd]\n",
                        crypt_stat->cipher, (int)strlen(crypt_stat->cipher),
                        crypt_stat->key_size << 3);
        if (crypt_stat->tfm) {
@@ -833,13 +833,13 @@ void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat)
        set_extent_mask_and_shift(crypt_stat);
        crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES;
        if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
-               crypt_stat->num_header_bytes_at_front = 0;
+               crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
        else {
                if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
-                       crypt_stat->num_header_bytes_at_front =
+                       crypt_stat->metadata_size =
                                ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
                else
-                       crypt_stat->num_header_bytes_at_front = PAGE_CACHE_SIZE;
+                       crypt_stat->metadata_size = PAGE_CACHE_SIZE;
        }
 }
 
@@ -1106,9 +1106,9 @@ static void write_ecryptfs_marker(char *page_virt, size_t *written)
        (*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
 }
 
-static void
-write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat,
-                    size_t *written)
+void ecryptfs_write_crypt_stat_flags(char *page_virt,
+                                    struct ecryptfs_crypt_stat *crypt_stat,
+                                    size_t *written)
 {
        u32 flags = 0;
        int i;
@@ -1213,14 +1213,15 @@ int ecryptfs_read_and_validate_header_region(char *data,
                crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE;
        rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size,
                                 ecryptfs_inode);
-       if (rc) {
+       if (rc < 0) {
                printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n",
                       __func__, rc);
                goto out;
        }
        if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) {
                rc = -EINVAL;
-       }
+       } else
+               rc = 0;
 out:
        return rc;
 }
@@ -1235,8 +1236,7 @@ ecryptfs_write_header_metadata(char *virt,
 
        header_extent_size = (u32)crypt_stat->extent_size;
        num_header_extents_at_front =
-               (u16)(crypt_stat->num_header_bytes_at_front
-                     / crypt_stat->extent_size);
+               (u16)(crypt_stat->metadata_size / crypt_stat->extent_size);
        put_unaligned_be32(header_extent_size, virt);
        virt += 4;
        put_unaligned_be16(num_header_extents_at_front, virt);
@@ -1289,7 +1289,8 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t max,
        offset = ECRYPTFS_FILE_SIZE_BYTES;
        write_ecryptfs_marker((page_virt + offset), &written);
        offset += written;
-       write_ecryptfs_flags((page_virt + offset), crypt_stat, &written);
+       ecryptfs_write_crypt_stat_flags((page_virt + offset), crypt_stat,
+                                       &written);
        offset += written;
        ecryptfs_write_header_metadata((page_virt + offset), crypt_stat,
                                       &written);
@@ -1315,10 +1316,11 @@ ecryptfs_write_metadata_to_contents(struct dentry *ecryptfs_dentry,
 
        rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, virt,
                                  0, virt_len);
-       if (rc)
+       if (rc < 0)
                printk(KERN_ERR "%s: Error attempting to write header "
-                      "information to lower file; rc = [%d]\n", __func__,
-                      rc);
+                      "information to lower file; rc = [%d]\n", __func__, rc);
+       else
+               rc = 0;
        return rc;
 }
 
@@ -1378,7 +1380,7 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry)
                rc = -EINVAL;
                goto out;
        }
-       virt_len = crypt_stat->num_header_bytes_at_front;
+       virt_len = crypt_stat->metadata_size;
        order = get_order(virt_len);
        /* Released in this function */
        virt = (char *)ecryptfs_get_zeroed_pages(GFP_KERNEL, order);
@@ -1424,16 +1426,15 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
        header_extent_size = get_unaligned_be32(virt);
        virt += sizeof(__be32);
        num_header_extents_at_front = get_unaligned_be16(virt);
-       crypt_stat->num_header_bytes_at_front =
-               (((size_t)num_header_extents_at_front
-                 * (size_t)header_extent_size));
+       crypt_stat->metadata_size = (((size_t)num_header_extents_at_front
+                                    * (size_t)header_extent_size));
        (*bytes_read) = (sizeof(__be32) + sizeof(__be16));
        if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE)
-           && (crypt_stat->num_header_bytes_at_front
+           && (crypt_stat->metadata_size
                < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) {
                rc = -EINVAL;
                printk(KERN_WARNING "Invalid header size: [%zd]\n",
-                      crypt_stat->num_header_bytes_at_front);
+                      crypt_stat->metadata_size);
        }
        return rc;
 }
@@ -1448,8 +1449,26 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
  */
 static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
 {
-       crypt_stat->num_header_bytes_at_front =
-               ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
+       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;
 }
 
 /**
@@ -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);
@@ -1598,11 +1619,12 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
        }
        rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size,
                                 ecryptfs_inode);
-       if (!rc)
+       if (rc >= 0)
                rc = ecryptfs_read_headers_virt(page_virt, crypt_stat,
                                                ecryptfs_dentry,
                                                ECRYPTFS_VALIDATE_HEADER_SIZE);
        if (rc) {
+               memset(page_virt, 0, PAGE_CACHE_SIZE);
                rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode);
                if (rc) {
                        printk(KERN_DEBUG "Valid eCryptfs headers not found in "
@@ -1745,7 +1767,7 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm,
                            char *cipher_name, size_t *key_size)
 {
        char dummy_key[ECRYPTFS_MAX_KEY_BYTES];
-       char *full_alg_name;
+       char *full_alg_name = NULL;
        int rc;
 
        *key_tfm = NULL;
@@ -1760,7 +1782,6 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm,
        if (rc)
                goto out;
        *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC);
-       kfree(full_alg_name);
        if (IS_ERR(*key_tfm)) {
                rc = PTR_ERR(*key_tfm);
                printk(KERN_ERR "Unable to allocate crypto cipher with name "
@@ -1783,6 +1804,7 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm,
                goto out;
        }
 out:
+       kfree(full_alg_name);
        return rc;
 }
 
@@ -1790,7 +1812,7 @@ struct kmem_cache *ecryptfs_key_tfm_cache;
 static struct list_head key_tfm_list;
 struct mutex key_tfm_list_mutex;
 
-int ecryptfs_init_crypto(void)
+int __init ecryptfs_init_crypto(void)
 {
        mutex_init(&key_tfm_list_mutex);
        INIT_LIST_HEAD(&key_tfm_list);
@@ -2166,7 +2188,6 @@ int ecryptfs_encrypt_and_encode_filename(
                                (ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE
                                 + encoded_name_no_prefix_size);
                        (*encoded_name)[(*encoded_name_size)] = '\0';
-                       (*encoded_name_size)++;
                } else {
                        rc = -EOPNOTSUPP;
                }