From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Megha Dey <megha.dey@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
Eric Biggers <ebiggers@kernel.org>,
Tim Chen <tim.c.chen@linux.intel.com>,
"David S. Miller" <davem@davemloft.net>,
syzbot <syzbot+d5455bac3ba1ee9114e5@syzkaller.appspotmail.com>,
"open list:HARDWARE RANDOM NUMBER GENERATOR CORE"
<linux-crypto@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
"the arch/x86 maintainers" <x86@kernel.org>
Subject: Re: KASAN: use-after-free Read in sha512_ctx_mgr_resubmit
Date: Tue, 28 Aug 2018 01:01:00 +0200 [thread overview]
Message-ID: <CAKv+Gu_oZ0Z37WV1h4opi-cYZT5FWU_bmrkBjx8LXpvKpPoZNA@mail.gmail.com> (raw)
In-Reply-To: <1535411336.3516.2.camel@megha-Z97X-UD7-TH>
On 28 August 2018 at 01:08, Megha Dey <megha.dey@linux.intel.com> wrote:
> On Wed, 2018-08-22 at 14:20 +0800, Herbert Xu wrote:
>> On Tue, Aug 21, 2018 at 02:43:56PM +0200, Ard Biesheuvel wrote:
>> >
>> > I agree. The code is obviously broken in a way that would have been
>> > noticed if it were in wide use, and it is too complicated for mere
>> > mortals to fix or maintain. I suggest we simply remove it for now, and
>> > if anyone wants to reintroduce it, we can review the code *and* the
>> > justification for the approach from scratch (in which case we should
>> > consider factoring out the algo agnostics plumbing in a way that
>> > allows it to be reused by other architectures as well)
>>
>> I agree too. Could one of you guys send me a patch to remove
>> them?
>>
>
> Hi,
>
> We are working on a fix to solve these corner cases.
>
Great. thanks.
But it would also be helpful if you could try and answer the questions
raised by Eric:
- in which cases does this driver result in a speedup?
- how should we tune the flush delay to prevent pathological
performance regressions?
- is it still safe in the post-Spectre era of computing to aggregate
hash input from different sources (which may be different users
altogether) and process them as a single source of input?
next prev parent reply other threads:[~2018-08-27 23:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-15 16:00 KASAN: use-after-free Read in sha512_ctx_mgr_resubmit syzbot
2018-08-20 7:31 ` Eric Biggers
2018-08-21 12:43 ` Ard Biesheuvel
2018-08-22 6:20 ` Herbert Xu
2018-08-27 23:08 ` Megha Dey
2018-08-27 23:01 ` Ard Biesheuvel [this message]
2018-08-28 22:17 ` Megha Dey
2018-10-05 22:33 ` Eric Biggers
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