btrfs: ensure that file descriptor used with subvol ioctls is a dir

[firefly-linux-kernel-4.4.55.git] / fs / btrfs / ioctl.c

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 65f30b3b04f91d54fc1bd9def4440d72fa077189..a7e18dbadf748ebaea90da93d982c2369a356833 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1619,6 +1619,9 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
        int namelen;
        int ret = 0;
 
+       if (!S_ISDIR(file_inode(file)->i_mode))
+               return -ENOTDIR;
+
        ret = mnt_want_write_file(file);
        if (ret)
                goto out;
@@ -1676,6 +1679,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
        struct btrfs_ioctl_vol_args *vol_args;
        int ret;
 
+       if (!S_ISDIR(file_inode(file)->i_mode))
+               return -ENOTDIR;
+
        vol_args = memdup_user(arg, sizeof(*vol_args));
        if (IS_ERR(vol_args))
                return PTR_ERR(vol_args);
@@ -1699,6 +1705,9 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
        bool readonly = false;
        struct btrfs_qgroup_inherit *inherit = NULL;
 
+       if (!S_ISDIR(file_inode(file)->i_mode))
+               return -ENOTDIR;
+
        vol_args = memdup_user(arg, sizeof(*vol_args));
        if (IS_ERR(vol_args))
                return PTR_ERR(vol_args);
@@ -2345,6 +2354,9 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
        int ret;
        int err = 0;
 
+       if (!S_ISDIR(dir->i_mode))
+               return -ENOTDIR;
+
        vol_args = memdup_user(arg, sizeof(*vol_args));
        if (IS_ERR(vol_args))
                return PTR_ERR(vol_args);