From: Andi Kleen <ak@linux.intel.com>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Paul Turner <pjt@google.com>,
Andrey Konovalov <andreyknvl@google.com>,
Kostya Serebryany <kcc@google.com>
Subject: Re: Out-of-bounds access in get_wchan (arch/x86/kernel/process_64.c)
Date: Tue, 10 Sep 2013 15:06:38 -0700 [thread overview]
Message-ID: <20130910220638.GG11427@tassilo.jf.intel.com> (raw)
In-Reply-To: <CACT4Y+Y6r=HV7nFgbu=B=d-4ka3J4yotRjgX1M1xGkNkFn1sOQ@mail.gmail.com>
> Indeed, get_wchan ensures that fp<stack+THREAD_SIZE, but then dereferences fp+8:
>
> 434 if (fp < (unsigned long)stack ||
> 435 fp >= (unsigned long)stack+THREAD_SIZE)
> 436 return 0;
> 437 ip = *(u64 *)(fp+8);
>
> It must check that fp+8<stack+THREAD_SIZE.
> As far as I see, the bug can lead to garbage return values or in the
> worst case to crash.
Thanks for the report.
The change looks good to me. Can you please submit a formal signed off patch
to x86@kernel.org ?
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2013-09-10 22:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-03 14:41 Out-of-bounds access in get_wchan (arch/x86/kernel/process_64.c) Dmitry Vyukov
2013-09-10 22:06 ` Andi Kleen [this message]
2013-09-11 18:16 ` Dmitry Vyukov
2013-09-27 19:03 ` Kees Cook
2013-09-28 19:51 ` Wolfram Gloger
2013-09-28 21:01 ` Kees Cook
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