1 files changed, 12 insertions, 37 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index db84aa48ab7a..2624b53ea783 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -457,15 +457,9 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
-
-	if (!vol_args)
-		return -ENOMEM;
-
-	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
-		ret = -EFAULT;
-		goto out;
-	}
+	vol_args = memdup_user(arg, sizeof(*vol_args));
+	if (IS_ERR(vol_args))
+		return PTR_ERR(vol_args);
 
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 	namelen = strlen(vol_args->name);
@@ -543,7 +537,6 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
 
 out_unlock:
 	mutex_unlock(&root->fs_info->volume_mutex);
-out:
 	kfree(vol_args);
 	return ret;
 }
@@ -563,15 +556,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
 	if (root->fs_info->sb->s_flags & MS_RDONLY)
 		return -EROFS;
 
-	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
-
-	if (!vol_args)
-		return -ENOMEM;
-
-	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
-		ret = -EFAULT;
-		goto out;
-	}
+	vol_args = memdup_user(arg, sizeof(*vol_args));
+	if (IS_ERR(vol_args))
+		return PTR_ERR(vol_args);
 
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 	namelen = strlen(vol_args->name);
@@ -673,19 +660,13 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+	vol_args = memdup_user(arg, sizeof(*vol_args));
+	if (IS_ERR(vol_args))
+		return PTR_ERR(vol_args);
 
-	if (!vol_args)
-		return -ENOMEM;
-
-	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
-		ret = -EFAULT;
-		goto out;
-	}
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 	ret = btrfs_init_new_device(root, vol_args->name);
 
-out:
 	kfree(vol_args);
 	return ret;
 }
@@ -701,19 +682,13 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
 	if (root->fs_info->sb->s_flags & MS_RDONLY)
 		return -EROFS;
 
-	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+	vol_args = memdup_user(arg, sizeof(*vol_args));
+	if (IS_ERR(vol_args))
+		return PTR_ERR(vol_args);
 
-	if (!vol_args)
-		return -ENOMEM;
-
-	if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
-		ret = -EFAULT;
-		goto out;
-	}
 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 	ret = btrfs_rm_device(root, vol_args->name);
 
-out:
 	kfree(vol_args);
 	return ret;
 }