1 files changed, 174 insertions, 107 deletions

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 992cf95830b5..7929411837cf 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -1,4 +1,5 @@
-/**
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
  * eCryptfs: Linux filesystem encryption layer
  *
  * Copyright (C) 1997-2004 Erez Zadok
@@ -6,21 +7,6 @@
  * Copyright (C) 2004-2007 International Business Machines Corp.
  *   Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
  *   		Michael C. Thompson <mcthomps@us.ibm.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
- * 02111-1307, USA.
  */
 
 #include <linux/file.h>
@@ -31,10 +17,9 @@
 #include <linux/security.h>
 #include <linux/compat.h>
 #include <linux/fs_stack.h>
-#include <linux/aio.h>
 #include "ecryptfs_kernel.h"
 
-/**
+/*
  * ecryptfs_read_update_atime
  *
  * generic_file_read updates the atime of upper layer inode.  But, it
@@ -45,23 +30,39 @@
  * The function to be used for directory reads is ecryptfs_read.
  */
 static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
-				const struct iovec *iov,
-				unsigned long nr_segs, loff_t pos)
+				struct iov_iter *to)
 {
 	ssize_t rc;
-	struct path *path;
 	struct file *file = iocb->ki_filp;
 
-	rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
-	/*
-	 * Even though this is a async interface, we need to wait
-	 * for IO to finish to update atime
-	 */
-	if (-EIOCBQUEUED == rc)
-		rc = wait_on_sync_kiocb(iocb);
+	rc = generic_file_read_iter(iocb, to);
 	if (rc >= 0) {
-		path = ecryptfs_dentry_to_lower_path(file->f_path.dentry);
-		touch_atime(path);
+		struct path path = ecryptfs_lower_path(file->f_path.dentry);
+		touch_atime(&path);
+	}
+	return rc;
+}
+
+/*
+ * ecryptfs_splice_read_update_atime
+ *
+ * filemap_splice_read updates the atime of upper layer inode.  But, it
+ * doesn't give us a chance to update the atime of the lower layer inode.  This
+ * function is a wrapper to generic_file_read.  It updates the atime of the
+ * lower level inode if generic_file_read returns without any errors. This is
+ * to be used only for file reads.  The function to be used for directory reads
+ * is ecryptfs_read.
+ */
+static ssize_t ecryptfs_splice_read_update_atime(struct file *in, loff_t *ppos,
+						 struct pipe_inode_info *pipe,
+						 size_t len, unsigned int flags)
+{
+	ssize_t rc;
+
+	rc = filemap_splice_read(in, ppos, pipe, len, flags);
+	if (rc >= 0) {
+		struct path path = ecryptfs_lower_path(in->f_path.dentry);
+		touch_atime(&path);
 	}
 	return rc;
 }
@@ -75,33 +76,44 @@ struct ecryptfs_getdents_callback {
 };
 
 /* Inspired by generic filldir in fs/readdir.c */
-static int
-ecryptfs_filldir(void *dirent, const char *lower_name, int lower_namelen,
-		 loff_t offset, u64 ino, unsigned int d_type)
+static bool
+ecryptfs_filldir(struct dir_context *ctx, const char *lower_name,
+		 int lower_namelen, loff_t offset, u64 ino, unsigned int d_type)
 {
 	struct ecryptfs_getdents_callback *buf =
-	    (struct ecryptfs_getdents_callback *)dirent;
+		container_of(ctx, struct ecryptfs_getdents_callback, ctx);
 	size_t name_size;
 	char *name;
-	int rc;
+	int err;
+	bool res;
 
 	buf->filldir_called++;
-	rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
-						  buf->sb, lower_name,
-						  lower_namelen);
-	if (rc) {
-		printk(KERN_ERR "%s: Error attempting to decode and decrypt "
-		       "filename [%s]; rc = [%d]\n", __func__, lower_name,
-		       rc);
-		goto out;
+	err = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
+						   buf->sb, lower_name,
+						   lower_namelen);
+	if (err) {
+		if (err != -EINVAL) {
+			ecryptfs_printk(KERN_DEBUG,
+					"%s: Error attempting to decode and decrypt filename [%s]; rc = [%d]\n",
+					__func__, lower_name, err);
+			return false;
+		}
+
+		/* Mask -EINVAL errors as these are most likely due a plaintext
+		 * filename present in the lower filesystem despite filename
+		 * encryption being enabled. One unavoidable example would be
+		 * the "lost+found" dentry in the root directory of an Ext4
+		 * filesystem.
+		 */
+		return true;
 	}
+
 	buf->caller->pos = buf->ctx.pos;
-	rc = !dir_emit(buf->caller, name, name_size, ino, d_type);
+	res = dir_emit(buf->caller, name, name_size, ino, d_type);
 	kfree(name);
-	if (!rc)
+	if (res)
 		buf->entries_written++;
-out:
-	return rc;
+	return res;
 }
 
 /**
@@ -120,17 +132,10 @@ static int ecryptfs_readdir(struct file *file, struct dir_context *ctx)
 		.sb = inode->i_sb,
 	};
 	lower_file = ecryptfs_file_to_lower(file);
-	lower_file->f_pos = ctx->pos;
 	rc = iterate_dir(lower_file, &buf.ctx);
 	ctx->pos = buf.ctx.pos;
-	if (rc < 0)
-		goto out;
-	if (buf.filldir_called && !buf.entries_written)
-		goto out;
-	if (rc >= 0)
-		fsstack_copy_attr_atime(inode,
-					file_inode(lower_file));
-out:
+	if (rc >= 0 && (buf.entries_written || !buf.filldir_called))
+		fsstack_copy_attr_atime(inode, file_inode(lower_file));
 	return rc;
 }
 
@@ -138,7 +143,7 @@ struct kmem_cache *ecryptfs_file_info_cache;
 
 static int read_or_initialize_metadata(struct dentry *dentry)
 {
-	struct inode *inode = dentry->d_inode;
+	struct inode *inode = d_inode(dentry);
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
 	struct ecryptfs_crypt_stat *crypt_stat;
 	int rc;
@@ -178,9 +183,22 @@ out:
 	return rc;
 }
 
+static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct file *lower_file = ecryptfs_file_to_lower(file);
+	/*
+	 * Don't allow mmap on top of file systems that don't support it
+	 * natively.  If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs
+	 * allows recursive mounting, this will need to be extended.
+	 */
+	if (!can_mmap_file(lower_file))
+		return -ENODEV;
+	return generic_file_mmap(file, vma);
+}
+
 /**
  * ecryptfs_open
- * @inode: inode speciying file to open
+ * @inode: inode specifying file to open
  * @file: Structure to return filled in
  *
  * Opens the file specified by inode.
@@ -191,23 +209,11 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 {
 	int rc = 0;
 	struct ecryptfs_crypt_stat *crypt_stat = NULL;
-	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
 	struct dentry *ecryptfs_dentry = file->f_path.dentry;
 	/* Private value of ecryptfs_dentry allocated in
 	 * ecryptfs_lookup() */
 	struct ecryptfs_file_info *file_info;
 
-	mount_crypt_stat = &ecryptfs_superblock_to_private(
-		ecryptfs_dentry->d_sb)->mount_crypt_stat;
-	if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
-	    && ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR)
-		|| (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC)
-		|| (file->f_flags & O_APPEND))) {
-		printk(KERN_WARNING "Mount has encrypted view enabled; "
-		       "files may only be read\n");
-		rc = -EPERM;
-		goto out;
-	}
 	/* Released in ecryptfs_release or end of function if failure */
 	file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
 	ecryptfs_set_file_private(file, file_info);
@@ -230,8 +236,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 	if (rc) {
 		printk(KERN_ERR "%s: Error attempting to initialize "
 			"the lower file for the dentry with name "
-			"[%s]; rc = [%d]\n", __func__,
-			ecryptfs_dentry->d_name.name, rc);
+			"[%pd]; rc = [%d]\n", __func__,
+			ecryptfs_dentry, rc);
 		goto out_free;
 	}
 	if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE)
@@ -243,14 +249,6 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 	}
 	ecryptfs_set_file_lower(
 		file, ecryptfs_inode_to_private(inode)->lower_file);
-	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
-		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
-		mutex_lock(&crypt_stat->cs_mutex);
-		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
-		mutex_unlock(&crypt_stat->cs_mutex);
-		rc = 0;
-		goto out;
-	}
 	rc = read_or_initialize_metadata(ecryptfs_dentry);
 	if (rc)
 		goto out_put;
@@ -267,11 +265,51 @@ out:
 	return rc;
 }
 
+/**
+ * ecryptfs_dir_open
+ * @inode: inode specifying file to open
+ * @file: Structure to return filled in
+ *
+ * Opens the file specified by inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_dir_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 ecryptfs_file_info *file_info;
+	struct file *lower_file;
+	struct path path;
+
+	/* Released in ecryptfs_release or end of function if failure */
+	file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
+	ecryptfs_set_file_private(file, file_info);
+	if (unlikely(!file_info)) {
+		ecryptfs_printk(KERN_ERR,
+				"Error attempting to allocate memory\n");
+		return -ENOMEM;
+	}
+	path = ecryptfs_lower_path(ecryptfs_dentry);
+	lower_file = dentry_open(&path, file->f_flags, current_cred());
+	if (IS_ERR(lower_file)) {
+		printk(KERN_ERR "%s: Error attempting to initialize "
+			"the lower file for the dentry with name "
+			"[%pd]; rc = [%ld]\n", __func__,
+			ecryptfs_dentry, PTR_ERR(lower_file));
+		kmem_cache_free(ecryptfs_file_info_cache, file_info);
+		return PTR_ERR(lower_file);
+	}
+	ecryptfs_set_file_lower(file, lower_file);
+	return 0;
+}
+
 static int ecryptfs_flush(struct file *file, fl_owner_t td)
 {
 	struct file *lower_file = ecryptfs_file_to_lower(file);
 
-	if (lower_file->f_op && lower_file->f_op->flush) {
+	if (lower_file->f_op->flush) {
 		filemap_write_and_wait(file->f_mapping);
 		return lower_file->f_op->flush(lower_file, td);
 	}
@@ -287,12 +325,25 @@ static int ecryptfs_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+static int ecryptfs_dir_release(struct inode *inode, struct file *file)
+{
+	fput(ecryptfs_file_to_lower(file));
+	kmem_cache_free(ecryptfs_file_info_cache,
+			ecryptfs_file_to_private(file));
+	return 0;
+}
+
+static loff_t ecryptfs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+	return vfs_llseek(ecryptfs_file_to_lower(file), offset, whence);
+}
+
 static int
 ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 {
 	int rc;
 
-	rc = filemap_write_and_wait(file->f_mapping);
+	rc = file_write_and_wait(file);
 	if (rc)
 		return rc;
 
@@ -305,7 +356,7 @@ static int ecryptfs_fasync(int fd, struct file *file, int flag)
 	struct file *lower_file = NULL;
 
 	lower_file = ecryptfs_file_to_lower(file);
-	if (lower_file->f_op && lower_file->f_op->fasync)
+	if (lower_file->f_op->fasync)
 		rc = lower_file->f_op->fasync(fd, lower_file, flag);
 	return rc;
 }
@@ -313,63 +364,79 @@ static int ecryptfs_fasync(int fd, struct file *file, int flag)
 static long
 ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	struct file *lower_file = NULL;
+	struct file *lower_file = ecryptfs_file_to_lower(file);
 	long rc = -ENOTTY;
 
-	if (ecryptfs_file_to_private(file))
-		lower_file = ecryptfs_file_to_lower(file);
-	if (lower_file && lower_file->f_op && lower_file->f_op->unlocked_ioctl)
+	if (!lower_file->f_op->unlocked_ioctl)
+		return rc;
+
+	switch (cmd) {
+	case FITRIM:
+	case FS_IOC_GETFLAGS:
+	case FS_IOC_SETFLAGS:
+	case FS_IOC_GETVERSION:
+	case FS_IOC_SETVERSION:
 		rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
-	return rc;
+		fsstack_copy_attr_all(file_inode(file), file_inode(lower_file));
+
+		return rc;
+	default:
+		return rc;
+	}
 }
 
 #ifdef CONFIG_COMPAT
 static long
 ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	struct file *lower_file = NULL;
+	struct file *lower_file = ecryptfs_file_to_lower(file);
 	long rc = -ENOIOCTLCMD;
 
-	if (ecryptfs_file_to_private(file))
-		lower_file = ecryptfs_file_to_lower(file);
-	if (lower_file && lower_file->f_op && lower_file->f_op->compat_ioctl)
+	if (!lower_file->f_op->compat_ioctl)
+		return rc;
+
+	switch (cmd) {
+	case FITRIM:
+	case FS_IOC32_GETFLAGS:
+	case FS_IOC32_SETFLAGS:
+	case FS_IOC32_GETVERSION:
+	case FS_IOC32_SETVERSION:
 		rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
-	return rc;
+		fsstack_copy_attr_all(file_inode(file), file_inode(lower_file));
+
+		return rc;
+	default:
+		return rc;
+	}
 }
 #endif
 
 const struct file_operations ecryptfs_dir_fops = {
-	.iterate = ecryptfs_readdir,
+	.iterate_shared = ecryptfs_readdir,
 	.read = generic_read_dir,
 	.unlocked_ioctl = ecryptfs_unlocked_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = ecryptfs_compat_ioctl,
 #endif
-	.open = ecryptfs_open,
-	.flush = ecryptfs_flush,
-	.release = ecryptfs_release,
+	.open = ecryptfs_dir_open,
+	.release = ecryptfs_dir_release,
 	.fsync = ecryptfs_fsync,
-	.fasync = ecryptfs_fasync,
-	.splice_read = generic_file_splice_read,
-	.llseek = default_llseek,
+	.llseek = ecryptfs_dir_llseek,
 };
 
 const struct file_operations ecryptfs_main_fops = {
 	.llseek = generic_file_llseek,
-	.read = do_sync_read,
-	.aio_read = ecryptfs_read_update_atime,
-	.write = do_sync_write,
-	.aio_write = generic_file_aio_write,
-	.iterate = ecryptfs_readdir,
+	.read_iter = ecryptfs_read_update_atime,
+	.write_iter = generic_file_write_iter,
 	.unlocked_ioctl = ecryptfs_unlocked_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = ecryptfs_compat_ioctl,
 #endif
-	.mmap = generic_file_mmap,
+	.mmap = ecryptfs_mmap,
 	.open = ecryptfs_open,
 	.flush = ecryptfs_flush,
 	.release = ecryptfs_release,
 	.fsync = ecryptfs_fsync,
 	.fasync = ecryptfs_fasync,
-	.splice_read = generic_file_splice_read,
+	.splice_read = ecryptfs_splice_read_update_atime,
 };