Re: [PATCH] check for invalid flags in xfs_attrlist_by_handle

Timothy Shimmin
2008-06-24T02:47:57Z

Christoph Hellwig wrote:
> On Fri, Jun 20, 2008 at 03:41:51PM +1000, Timothy Shimmin wrote:
>> Fair enough.
>> Actually, I think we only use ATTR_ROOT and ATTR_SECURE for the
>> namespace flags.
>> So you could probably use: XFS_ATTR_NSP_ARGS
>> xfs_attr_leaf.h:#define XFS_ATTR_NSP_ARGS_MASK (ATTR_ROOT | ATTR_SECURE)
>> xfs_attr_leaf.h:#define XFS_ATTR_NSP_ARGS(flags) ((flags) & XFS_ATTR_NSP_ARGS_MASK)
>> and something like:
>>
>> if (!XFS_ATTR_NSP_ARGS(al_hreq.flags))
>> return -XFS_ERROR(EINVAL);
>
> Actually a zero flags is of course valid too.
>
Ah, that would be why I used the phrase "something like" ;-))
Good pt.

> So the check should be & ~(ATTR_ROOT | ATTR_SECURE). I could use
> XFS_ATTR_NSP_ARGS_MASK but that would pull in not just xfs_attr_leaf.h
> but also xfs_da_btree.h and that needs even more headers..
>
> So I propose this simple version:
>
Cool.
I was just thinking about centralising stuff in case we extend the
namespaces. But that's fine.
I'll check it in...

--Tim

>
> Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl.c
> ===================================================================
> --- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_ioctl.c 2008-06-20 08:17:13.000000000 +0200
> +++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl.c 2008-06-23 13:38:17.000000000 +0200
> @@ -470,6 +470,12 @@ xfs_attrlist_by_handle(
> if (al_hreq.buflen > XATTR_LIST_MAX)
> return -XFS_ERROR(EINVAL);
>
> + /*
> + * Reject flags, only allow namespaces.
> + */
> + if (al_hreq.flags & ~(ATTR_ROOT | ATTR_SECURE))
> + return -XFS_ERROR(EINVAL);
> +
> error = xfs_vget_fsop_handlereq(mp, parinode, &al_hreq.hreq, &inode);
> if (error)
> goto out;
>