Messages in this thread | | | Subject | Re: [PATCH] vsprintf: Make "null" pointer dereference more robust | From | Andy Shevchenko <> | Date | Mon, 05 Mar 2018 17:25:04 +0200 |
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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
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