btrfs: prevent to set invalid default subvolid

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / btrfs / ioctl.c

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index dbefa6c609f47bfb363c5e64399bd770cc9b10fc..7831e6865f16a33d9813f11d371b0acb3a0f0539 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1496,6 +1496,9 @@ 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;
@@ -1553,6 +1556,9 @@ 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);
@@ -1576,6 +1582,9 @@ 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);
@@ -2081,6 +2090,9 @@ 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);
@@ -2962,6 +2974,10 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
                ret = PTR_ERR(new_root);
                goto out;
        }
+       if (!is_fstree(new_root->objectid)) {
+               ret = -ENOENT;
+               goto out;
+       }
 
        if (btrfs_root_refs(&new_root->root_item) == 0) {
                ret = -ENOENT;