Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
  ecryptfs: use after free
  ecryptfs: Eliminate useless code
  ecryptfs: fix interpose/interpolate typos in comments
  ecryptfs: pass matching flags to interpose as defined and used there
  ecryptfs: remove unnecessary d_drop calls in ecryptfs_link
  ecryptfs: don't ignore return value from lock_rename
  ecryptfs: initialize private persistent file before dereferencing pointer
  eCryptfs: Remove mmap from directory operations
  eCryptfs: Add getattr function
  eCryptfs: Use notify_change for truncating lower inodes

4 files changed, 109 insertions, 50 deletions

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index fbb6e5e..7cb0a59 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1748,7 +1748,7 @@ 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;
@@ -1763,7 +1763,6 @@ 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 "
@@ -1786,6 +1785,7 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm,
 		goto out;
 	}
 out:
+	kfree(full_alg_name);
 	return rc;
 }
 
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 9e94405..678172b 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -158,7 +158,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 	struct dentry *ecryptfs_dentry = file->f_path.dentry;
 	/* Private value of ecryptfs_dentry allocated in
 	 * ecryptfs_lookup() */
-	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
+	struct dentry *lower_dentry;
 	struct ecryptfs_file_info *file_info;
 
 	mount_crypt_stat = &ecryptfs_superblock_to_private(
@@ -191,13 +191,6 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 				      | ECRYPTFS_ENCRYPTED);
 	}
 	mutex_unlock(&crypt_stat->cs_mutex);
-	if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY)
-	    && !(file->f_flags & O_RDONLY)) {
-		rc = -EPERM;
-		printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs "
-		       "file must hence be opened RO\n", __func__);
-		goto out;
-	}
 	if (!ecryptfs_inode_to_private(inode)->lower_file) {
 		rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
 		if (rc) {
@@ -208,6 +201,13 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 			goto out;
 		}
 	}
+	if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY)
+	    && !(file->f_flags & O_RDONLY)) {
+		rc = -EPERM;
+		printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs "
+		       "file must hence be opened RO\n", __func__);
+		goto out;
+	}
 	ecryptfs_set_file_lower(
 		file, ecryptfs_inode_to_private(inode)->lower_file);
 	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
@@ -299,7 +299,6 @@ static int ecryptfs_ioctl(struct inode *inode, struct file *file,
 const struct file_operations ecryptfs_dir_fops = {
 	.readdir = ecryptfs_readdir,
 	.ioctl = ecryptfs_ioctl,
-	.mmap = generic_file_mmap,
 	.open = ecryptfs_open,
 	.flush = ecryptfs_flush,
 	.release = ecryptfs_release,
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 7f85450..4a430ab 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -282,7 +282,8 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 		goto out;
 	}
 	rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
-				ecryptfs_dir_inode->i_sb, 1);
+				ecryptfs_dir_inode->i_sb,
+				ECRYPTFS_INTERPOSE_FLAG_D_ADD);
 	if (rc) {
 		printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
 		       __func__, rc);
@@ -463,9 +464,6 @@ out_lock:
 	unlock_dir(lower_dir_dentry);
 	dput(lower_new_dentry);
 	dput(lower_old_dentry);
-	d_drop(lower_old_dentry);
-	d_drop(new_dentry);
-	d_drop(old_dentry);
 	return rc;
 }
 
@@ -614,6 +612,7 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct dentry *lower_new_dentry;
 	struct dentry *lower_old_dir_dentry;
 	struct dentry *lower_new_dir_dentry;
+	struct dentry *trap = NULL;
 
 	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
 	lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
@@ -621,7 +620,17 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	dget(lower_new_dentry);
 	lower_old_dir_dentry = dget_parent(lower_old_dentry);
 	lower_new_dir_dentry = dget_parent(lower_new_dentry);
-	lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+	trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+	/* source should not be ancestor of target */
+	if (trap == lower_old_dentry) {
+		rc = -EINVAL;
+		goto out_lock;
+	}
+	/* target should not be ancestor of source */
+	if (trap == lower_new_dentry) {
+		rc = -ENOTEMPTY;
+		goto out_lock;
+	}
 	rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
 			lower_new_dir_dentry->d_inode, lower_new_dentry);
 	if (rc)
@@ -772,18 +781,23 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
 }
 
 /**
- * ecryptfs_truncate
+ * truncate_upper
  * @dentry: The ecryptfs layer dentry
- * @new_length: The length to expand the file to
+ * @ia: Address of the ecryptfs inode's attributes
+ * @lower_ia: Address of the lower inode's attributes
  *
  * Function to handle truncations modifying the size of the file. Note
  * that the file sizes are interpolated. When expanding, we are simply
- * writing strings of 0's out. When truncating, we need to modify the
- * underlying file size according to the page index interpolations.
+ * writing strings of 0's out. When truncating, we truncate the upper
+ * inode and update the lower_ia according to the page index
+ * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
+ * the caller must use lower_ia in a call to notify_change() to perform
+ * the truncation of the lower inode.
  *
  * Returns zero on success; non-zero otherwise
  */
-int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
+static int truncate_upper(struct dentry *dentry, struct iattr *ia,
+			  struct iattr *lower_ia)
 {
 	int rc = 0;
 	struct inode *inode = dentry->d_inode;
@@ -794,8 +808,10 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 	loff_t lower_size_before_truncate;
 	loff_t lower_size_after_truncate;
 
-	if (unlikely((new_length == i_size)))
+	if (unlikely((ia->ia_size == i_size))) {
+		lower_ia->ia_valid &= ~ATTR_SIZE;
 		goto out;
+	}
 	crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
 	/* Set up a fake ecryptfs file, this is used to interface with
 	 * the file in the underlying filesystem so that the
@@ -815,28 +831,30 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 		&fake_ecryptfs_file,
 		ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
 	/* Switch on growing or shrinking file */
-	if (new_length > i_size) {
+	if (ia->ia_size > i_size) {
 		char zero[] = { 0x00 };
 
+		lower_ia->ia_valid &= ~ATTR_SIZE;
 		/* Write a single 0 at the last position of the file;
 		 * this triggers code that will fill in 0's throughout
 		 * the intermediate portion of the previous end of the
 		 * file and the new and of the file */
 		rc = ecryptfs_write(&fake_ecryptfs_file, zero,
-				    (new_length - 1), 1);
-	} else { /* new_length < i_size_read(inode) */
-		/* We're chopping off all the pages down do the page
-		 * in which new_length is located. Fill in the end of
-		 * that page from (new_length & ~PAGE_CACHE_MASK) to
+				    (ia->ia_size - 1), 1);
+	} else { /* ia->ia_size < i_size_read(inode) */
+		/* We're chopping off all the pages down to the page
+		 * in which ia->ia_size is located. Fill in the end of
+		 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
 		 * PAGE_CACHE_SIZE with zeros. */
 		size_t num_zeros = (PAGE_CACHE_SIZE
-				    - (new_length & ~PAGE_CACHE_MASK));
+				    - (ia->ia_size & ~PAGE_CACHE_MASK));
 
 		if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
-			rc = vmtruncate(inode, new_length);
+			rc = vmtruncate(inode, ia->ia_size);
 			if (rc)
 				goto out_free;
-			rc = vmtruncate(lower_dentry->d_inode, new_length);
+			lower_ia->ia_size = ia->ia_size;
+			lower_ia->ia_valid |= ATTR_SIZE;
 			goto out_free;
 		}
 		if (num_zeros) {
@@ -848,7 +866,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 				goto out_free;
 			}
 			rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
-					    new_length, num_zeros);
+					    ia->ia_size, num_zeros);
 			kfree(zeros_virt);
 			if (rc) {
 				printk(KERN_ERR "Error attempting to zero out "
@@ -857,7 +875,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 				goto out_free;
 			}
 		}
-		vmtruncate(inode, new_length);
+		vmtruncate(inode, ia->ia_size);
 		rc = ecryptfs_write_inode_size_to_metadata(inode);
 		if (rc) {
 			printk(KERN_ERR	"Problem with "
@@ -870,10 +888,12 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
 		lower_size_before_truncate =
 		    upper_size_to_lower_size(crypt_stat, i_size);
 		lower_size_after_truncate =
-		    upper_size_to_lower_size(crypt_stat, new_length);
-		if (lower_size_after_truncate < lower_size_before_truncate)
-			vmtruncate(lower_dentry->d_inode,
-				   lower_size_after_truncate);
+		    upper_size_to_lower_size(crypt_stat, ia->ia_size);
+		if (lower_size_after_truncate < lower_size_before_truncate) {
+			lower_ia->ia_size = lower_size_after_truncate;
+			lower_ia->ia_valid |= ATTR_SIZE;
+		} else
+			lower_ia->ia_valid &= ~ATTR_SIZE;
 	}
 out_free:
 	if (ecryptfs_file_to_private(&fake_ecryptfs_file))
@@ -883,6 +903,33 @@ out:
 	return rc;
 }
 
+/**
+ * ecryptfs_truncate
+ * @dentry: The ecryptfs layer dentry
+ * @new_length: The length to expand the file to
+ *
+ * Simple function that handles the truncation of an eCryptfs inode and
+ * its corresponding lower inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
+{
+	struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
+	struct iattr lower_ia = { .ia_valid = 0 };
+	int rc;
+
+	rc = truncate_upper(dentry, &ia, &lower_ia);
+	if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
+		struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+
+		mutex_lock(&lower_dentry->d_inode->i_mutex);
+		rc = notify_change(lower_dentry, &lower_ia);
+		mutex_unlock(&lower_dentry->d_inode->i_mutex);
+	}
+	return rc;
+}
+
 static int
 ecryptfs_permission(struct inode *inode, int mask)
 {
@@ -905,6 +952,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 {
 	int rc = 0;
 	struct dentry *lower_dentry;
+	struct iattr lower_ia;
 	struct inode *inode;
 	struct inode *lower_inode;
 	struct ecryptfs_crypt_stat *crypt_stat;
@@ -943,15 +991,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 		}
 	}
 	mutex_unlock(&crypt_stat->cs_mutex);
+	memcpy(&lower_ia, ia, sizeof(lower_ia));
+	if (ia->ia_valid & ATTR_FILE)
+		lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
 	if (ia->ia_valid & ATTR_SIZE) {
-		ecryptfs_printk(KERN_DEBUG,
-				"ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
-				ia->ia_valid, ATTR_SIZE);
-		rc = ecryptfs_truncate(dentry, ia->ia_size);
-		/* ecryptfs_truncate handles resizing of the lower file */
-		ia->ia_valid &= ~ATTR_SIZE;
-		ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
-				ia->ia_valid);
+		rc = truncate_upper(dentry, ia, &lower_ia);
 		if (rc < 0)
 			goto out;
 	}
@@ -960,17 +1004,32 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 	 * mode change is for clearing setuid/setgid bits. Allow lower fs
 	 * to interpret this in its own way.
 	 */
-	if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
-		ia->ia_valid &= ~ATTR_MODE;
+	if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+		lower_ia.ia_valid &= ~ATTR_MODE;
 
 	mutex_lock(&lower_dentry->d_inode->i_mutex);
-	rc = notify_change(lower_dentry, ia);
+	rc = notify_change(lower_dentry, &lower_ia);
 	mutex_unlock(&lower_dentry->d_inode->i_mutex);
 out:
 	fsstack_copy_attr_all(inode, lower_inode);
 	return rc;
 }
 
+int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
+		     struct kstat *stat)
+{
+	struct kstat lower_stat;
+	int rc;
+
+	rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
+			 ecryptfs_dentry_to_lower(dentry), &lower_stat);
+	if (!rc) {
+		generic_fillattr(dentry->d_inode, stat);
+		stat->blocks = lower_stat.blocks;
+	}
+	return rc;
+}
+
 int
 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 		  size_t size, int flags)
@@ -1100,6 +1159,7 @@ const struct inode_operations ecryptfs_dir_iops = {
 const struct inode_operations ecryptfs_main_iops = {
 	.permission = ecryptfs_permission,
 	.setattr = ecryptfs_setattr,
+	.getattr = ecryptfs_getattr,
 	.setxattr = ecryptfs_setxattr,
 	.getxattr = ecryptfs_getxattr,
 	.listxattr = ecryptfs_listxattr,
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 567bc4b..ea2f921 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -585,8 +585,8 @@ out:
  *                        with as much information as it can before needing
  *                        the lower filesystem.
  * ecryptfs_read_super(): this accesses the lower filesystem and uses
- *                        ecryptfs_interpolate to perform most of the linking
- * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
+ *                        ecryptfs_interpose to perform most of the linking
+ * ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c)
  */
 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
 			const char *dev_name, void *raw_data,