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

[Andrew Morton <akpm@osdl.org>]

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()?