Re: [patch 1/1] net: convert %p usage to %pK

[Joe Perches <joe@perches.com>]

On Tue, 2011-05-24 at 08:17 +0200, Eric Dumazet wrote:
> We probably need to extend this to inet_diag as well.
> Provide a mayber_hide_ptr() helper and use it in inet_diag to not
> disclose kernel pointers to user, with kptr_restrict logic :
> kptr_restrict = 0 : kernel pointers are not mangled
> kptr_restrict = 1 : if the current user does not have CAP_SYSLOG,
> kernel pointers are replaced by 0
> kptr_restrict = 2 : kernel pointers are replaced by 0
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
[]
> +void *maybe_hide_ptr(void *ptr)
> +{
> +	if (!((kptr_restrict == 0) ||
> +	      (kptr_restrict == 1 &&
> +	       has_capability_noaudit(current, CAP_SYSLOG))))
> +		ptr = NULL;
> +	return ptr;
> +}
> +EXPORT_SYMBOL(maybe_hide_ptr);

Makes sense to me.

Maybe for clarity it'd be better to use a switch/case
or something like:

	if (kptr_restrict == 0)
		return ptr;
	if (ptr_restrict == 1 &&
	    has_capability_noaudit(current, CAP_SYSLOG))
		return ptr;
	return NULL;