Re: [PATCH] prohibit slash in proc directory entry names

[Nathan Lynch <nathanl@austin.ibm.com>]

On Wed, 2005-01-05 at 16:07 -0800, Andrew Morton wrote:
> Nathan Lynch <nathanl@austin.ibm.com> wrote:
> >
> > proc_create() needs to check that the name of an entry to be created
> >  does not contain a '/' character.
> > 
> >  To test, I hacked the ibmveth driver to try to call request_irq with a
> >  bogus "foo/bar" devname.  The creation of the /proc/irq/1234/xxx entry
> >  silently fails, as intended.  Perhaps the irq code should be made to
> >  check for the failure.
> > 
> >  Signed-off-by: Nathan Lynch <nathanl@austin.ibm.com>
> > 
> >  Index: 2.6.10/fs/proc/generic.c
> >  ===================================================================
> >  --- 2.6.10.orig/fs/proc/generic.c	2004-12-24 21:35:40.000000000 +0000
> >  +++ 2.6.10/fs/proc/generic.c	2005-01-05 18:44:56.000000000 +0000
> >  @@ -551,6 +551,11 @@
> >   
> >   	if (!(*parent) && xlate_proc_name(name, parent, &fn) != 0)
> >   		goto out;
> >  +
> >  +	/* At this point there must not be any '/' characters beyond *fn */
> >  +	if (strchr(fn, '/'))
> >  +		goto out;
> >  +
> 
> hm.  From a brief code-squint I don't see how the string can ever have a
> slash in it by this stage.  Unless the caller provided a non-null *parent
> and we never called xlate_proc_name()?

Right.