@@ -1227,9 +1227,6 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
int ret;
int err = 0;
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
@@ -1264,6 +1261,28 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
goto out_dput;
}
+ /*
+ * Allow subvol deletion if we own the subvol and we would
+ * (approximately) be allowed to rmdir it. Strictly speaking,
+ * we could possibly delete everything with fewer permissions,
+ * or might require more permissions to remove all files
+ * contained by the subvol, but we aren't trying to mimic
+ * directory semantics perfectly.
+ */
+ err = inode_permission(dir, MAY_WRITE | MAY_EXEC);
+ if (err)
+ goto out_dput;
+ err = security_inode_rmdir(dir, dentry);
+ if (err)
+ goto out_dput;
+ err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
+ if (err)
+ goto out_dput;
+ err = -EPERM;
+ if (inode->i_uid != current_fsuid() || IS_APPEND(dir) ||
+ IS_APPEND(inode))
+ goto out_dput;
+
dest = BTRFS_I(inode)->root;
mutex_lock(&inode->i_mutex);