linux-kernel - Re: [PATCH 6/6] kasan: improve double-free reports.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 2 Aug 2016 14:53:50 +0200
From:	Alexander Potapenko <glider@...gle.com>
To:	Andrey Ryabinin <aryabinin@...tuozzo.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Dave Jones <davej@...emonkey.org.uk>,
	Vegard Nossum <vegard.nossum@...cle.com>,
	Sasha Levin <alexander.levin@...izon.com>,
	Dmitry Vyukov <dvyukov@...gle.com>,
	kasan-dev <kasan-dev@...glegroups.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Linux Memory Management List <linux-mm@...ck.org>
Subject: Re: [PATCH 6/6] kasan: improve double-free reports.

On Tue, Aug 2, 2016 at 2:34 PM, Andrey Ryabinin <aryabinin@...tuozzo.com> wrote:
>
>
> On 08/02/2016 02:39 PM, Alexander Potapenko wrote:
>
>>> +static void kasan_end_report(unsigned long *flags)
>>> +{
>>> +       pr_err("==================================================================\n");
>>> +       add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
>> Don't we want to add the taint as early as possible once we've
>> detected the error?
>
> What for?
> It certainly shouldn't be before dump_stack(), otherwise on the first report the kernel will claimed as tainted.
Ah, got it. Fair enough.
>
>>>
>>> +void kasan_report_double_free(struct kmem_cache *cache, void *object,
>>> +                       s8 shadow)
>>> +{
>>> +       unsigned long flags;
>>> +
>>> +       kasan_start_report(&flags);
>>> +       pr_err("BUG: Double free or corrupt pointer\n");
>> How about "Double free or freeing an invalid pointer\n"?
>> I think "corrupt pointer" doesn't exactly reflect where the bug is.
>
> Ok
>



-- 
Alexander Potapenko
Software Engineer

Google Germany GmbH
Erika-Mann-Straße, 33
80636 München

Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg