[patch] fuse: fix permission checking

[patch] fuse: fix permission checking

[Miklos Szeredi]

This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.

Thanks,
Miklos
----

From: Miklos Szeredi <mszeredi@suse.cz>

I added a nasty local variable shadowing bug to fuse in 2.6.24, with
the result, that the 'default_permissions' mount option is basically
ignored.

How did this happen?

 - old err declaration in inner scope
 - new err getting declared in outer scope
 - 'return err' from inner scope getting removed
 - old declaration not being noticed

-Wshadow would have saved us, but it doesn't seem practical for
the kernel :(

More testing would have also saved us :((

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---

Index: linux/fs/fuse/dir.c
===================================================================
--- linux.orig/fs/fuse/dir.c	2008-02-15 10:46:06.000000000 +0100
+++ linux/fs/fuse/dir.c	2008-02-15 11:05:46.000000000 +0100
@@ -906,7 +906,7 @@ static int fuse_permission(struct inode 
 	}
 
 	if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
-		int err = generic_permission(inode, mask, NULL);
+		err = generic_permission(inode, mask, NULL);
 
 		/* If permission is denied, try to refresh file
 		   attributes.  This is also needed, because the root

Re: [patch] fuse: fix permission checking

[Harvey Harrison]

On Fri, 2008-02-15 at 11:23 +0100, Miklos Szeredi wrote:
> This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.
> 
> Thanks,
> Miklos
> ----
> 
> From: Miklos Szeredi <mszeredi@suse.cz>
> 
> I added a nasty local variable shadowing bug to fuse in 2.6.24, with
> the result, that the 'default_permissions' mount option is basically
> ignored.
> 
> How did this happen?
> 
>  - old err declaration in inner scope
>  - new err getting declared in outer scope
>  - 'return err' from inner scope getting removed
>  - old declaration not being noticed
> 
> -Wshadow would have saved us, but it doesn't seem practical for
> the kernel :(
> 
> More testing would have also saved us :((

sparse would have saved you too.

Harvey

Re: [stable] [patch] fuse: fix permission checking

[Greg KH]

On Fri, Feb 15, 2008 at 11:23:47AM +0100, Miklos Szeredi wrote:
> This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.
> 
> Thanks,
> Miklos
> ----
> 
> From: Miklos Szeredi <mszeredi@suse.cz>
> 
> I added a nasty local variable shadowing bug to fuse in 2.6.24, with
> the result, that the 'default_permissions' mount option is basically
> ignored.

When this goes into Linus's tree, can you let us know along with the git
commit id?

thanks,

greg k-h

Re: [stable] [patch] fuse: fix permission checking

[Miklos Szeredi]

> On Fri, Feb 15, 2008 at 11:23:47AM +0100, Miklos Szeredi wrote:
> > This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.
> > 
> > Thanks,
> > Miklos
> > ----
> > 
> > From: Miklos Szeredi <mszeredi@suse.cz>
> > 
> > I added a nasty local variable shadowing bug to fuse in 2.6.24, with
> > the result, that the 'default_permissions' mount option is basically
> > ignored.
> 
> When this goes into Linus's tree, can you let us know along with the git
> commit id?

I'd really like to see this in 2.6.24.3.  How much time is left?
Should I bypass Andrew and submit to Linus ASAP?

Thanks,
Miklos

Re: [stable] [patch] fuse: fix permission checking

[Greg KH]

On Sat, Feb 23, 2008 at 10:38:59AM +0100, Miklos Szeredi wrote:
> > On Fri, Feb 15, 2008 at 11:23:47AM +0100, Miklos Szeredi wrote:
> > > This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.
> > > 
> > > Thanks,
> > > Miklos
> > > ----
> > > 
> > > From: Miklos Szeredi <mszeredi@suse.cz>
> > > 
> > > I added a nasty local variable shadowing bug to fuse in 2.6.24, with
> > > the result, that the 'default_permissions' mount option is basically
> > > ignored.
> > 
> > When this goes into Linus's tree, can you let us know along with the git
> > commit id?
> 
> I'd really like to see this in 2.6.24.3.  How much time is left?
> Should I bypass Andrew and submit to Linus ASAP?

There will be a .24.4 soon afterward (week or so), so don't feel like
you have to rush.  Unless this is some kind of security issue?

thanks,

greg k-h

Re: [stable] [patch] fuse: fix permission checking

[Andrew Morton]

On Sat, 23 Feb 2008 11:08:59 -0800 Greg KH <greg@kroah.com> wrote:

> On Sat, Feb 23, 2008 at 10:38:59AM +0100, Miklos Szeredi wrote:
> > > On Fri, Feb 15, 2008 at 11:23:47AM +0100, Miklos Szeredi wrote:
> > > > This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.
> > > > 
> > > > Thanks,
> > > > Miklos
> > > > ----
> > > > 
> > > > From: Miklos Szeredi <mszeredi@suse.cz>
> > > > 
> > > > I added a nasty local variable shadowing bug to fuse in 2.6.24, with
> > > > the result, that the 'default_permissions' mount option is basically
> > > > ignored.
> > > 
> > > When this goes into Linus's tree, can you let us know along with the git
> > > commit id?
> > 
> > I'd really like to see this in 2.6.24.3.  How much time is left?
> > Should I bypass Andrew and submit to Linus ASAP?
> 
> There will be a .24.4 soon afterward (week or so), so don't feel like
> you have to rush.  Unless this is some kind of security issue?
> 

I'll be sending a bunch of fixes to Linus this weekend, including this patch.

Re: [stable] [patch] fuse: fix permission checking

[Miklos Szeredi]

> > On Sat, Feb 23, 2008 at 10:38:59AM +0100, Miklos Szeredi wrote:
> > > > On Fri, Feb 15, 2008 at 11:23:47AM +0100, Miklos Szeredi wrote:
> > > > > This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.
> > > > > 
> > > > > Thanks,
> > > > > Miklos
> > > > > ----
> > > > > 
> > > > > From: Miklos Szeredi <mszeredi@suse.cz>
> > > > > 
> > > > > I added a nasty local variable shadowing bug to fuse in 2.6.24, with
> > > > > the result, that the 'default_permissions' mount option is basically
> > > > > ignored.
> > > > 
> > > > When this goes into Linus's tree, can you let us know along with the git
> > > > commit id?
> > > 
> > > I'd really like to see this in 2.6.24.3.  How much time is left?
> > > Should I bypass Andrew and submit to Linus ASAP?
> > 
> > There will be a .24.4 soon afterward (week or so), so don't feel like
> > you have to rush.  Unless this is some kind of security issue?
> > 
> 
> I'll be sending a bunch of fixes to Linus this weekend, including this patch.

Thanks.

Yes, this could have security implications, so the earlier, the better.

Miklos

Re: [stable] [patch] fuse: fix permission checking

[Miklos Szeredi]

Hi Greg!

> On Fri, Feb 15, 2008 at 11:23:47AM +0100, Miklos Szeredi wrote:
> > This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.
> > 
> > Thanks,
> > Miklos
> > ----
> > 
> > From: Miklos Szeredi <mszeredi@suse.cz>
> > 
> > I added a nasty local variable shadowing bug to fuse in 2.6.24, with
> > the result, that the 'default_permissions' mount option is basically
> > ignored.
> 
> When this goes into Linus's tree, can you let us know along with the git
> commit id?

It's now in Linus tree:

commit 1a823ac9ff09cbdf39201df37b7ede1f9395de83

Thanks,
Miklos