lkml.org 
[lkml]   [2018]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] vsprintf: Make "null" pointer dereference more robust
From
Date
On Mon, 2018-03-05 at 16:16 +0100, Rasmus Villemoes wrote:
> On 2 March 2018 at 13:53, Petr Mladek <pmladek@suse.com> wrote:

> > - if (!ptr && *fmt != 'K' && *fmt != 'x') {
> > + if ((unsigned long)ptr < PAGE_SIZE && *fmt != 'K' && *fmt !=
> > 'x') {
>
> ISTM that accidentally passing an ERR_PTR would be just as likely as
> passing a NULL pointer (or some small offset from one), so if we do
> this, shouldn't the test also cover IS_ERR values?

We (will) have such check in two places, perhaps a helper

static bool is_pointer_valid(void *ptr)
{
return !IS_ERR(ptr) && (unsigned long)ptr >= PAGE_SIZE;
}

?

--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

\
 
 \ /
  Last update: 2018-03-05 16:25    [W:0.160 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site