Re: [PATCH 0/2] Shared flags

3 messages, 3 authors, 2008-11-15 · open the first message on its own page

Re: [PATCH 0/2] Shared flags

From: Christoph Hellwig <hidden>
Date: 2008-11-13 09:25:54

On Thu, Nov 13, 2008 at 01:08:58PM +0300, Pavel Shilovsky wrote:
We suggest to switch on this flags with special options during mounting.  
By default, it'll be switch off.
This solution deletes possibility of such situations, like in example.
Sorry, having completely weird open modes only for one filesystem, and
only depending on mount options is not very nice to the user.

And options or not allowing the above functionality for regular users
is a security issue.

--
To unsubscribe from this list: send the line "unsubscribe linux-api" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 0/2] Shared flags

From: Jamie Lokier <hidden>
Date: 2008-11-14 03:37:23

Christoph Hellwig wrote:
On Thu, Nov 13, 2008 at 01:08:58PM +0300, Pavel Shilovsky wrote:
quoted
We suggest to switch on this flags with special options during mounting.  
By default, it'll be switch off.
This solution deletes possibility of such situations, like in example.
Sorry, having completely weird open modes only for one filesystem, and
only depending on mount options is not very nice to the user.

And options or not allowing the above functionality for regular users
is a security issue.
A generic mount option is currently used for mandatory locking - this
is very similar.

The only different I see, for security, is with mandatory locking a
process which doesn't want to get stuck can check the permission bits
before opening a file.  But I'm not aware of anything actually doing this.

-- Jamie

Re: [PATCH 0/2] Shared flags

From: Christoph Hellwig <hch@infradead.org>
Date: 2008-11-15 11:39:47

On Fri, Nov 14, 2008 at 03:37:12AM +0000, Jamie Lokier wrote:
A generic mount option is currently used for mandatory locking - this
is very similar.

The only different I see, for security, is with mandatory locking a
process which doesn't want to get stuck can check the permission bits
before opening a file.  But I'm not aware of anything actually doing this.
More importantly the admin can do it.  And mandatory locking doesn't
mean you can't remove something, with would be a complete nightmare.  It
also doesn't apply to directories, which from my reading of the patch
this one would do.  But yeah, doing the read/write part as as a special
case of mandlock on open might make some sense, but I'm still not too
convinced.

That more I think about these option the less I like the idea, it's just
going to cause a lot of problems to help with some wine issues that
hasn't even been explained yet.
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help