netdev - Re: [Bugme-new] [Bug 38102] New: BUG kmalloc-2048: Poison overwritten

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]

Message-ID: <CAB9v_DFM8PcujUB-YzcK49DS7T6Bz2FLDtkVdEYt8an1oPYVFw@mail.gmail.com>
Date:	Tue, 5 Jul 2011 08:57:15 +0400
From:	Alexey Zaytsev <alexey.zaytsev@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Michael Büsch <m@...s.ch>,
	Andrew Morton <akpm@...ux-foundation.org>,
	netdev@...r.kernel.org, Gary Zambrano <zambrano@...adcom.com>,
	bugme-daemon@...zilla.kernel.org,
	"David S. Miller" <davem@...emloft.net>,
	Pekka Pietikainen <pp@...oulu.fi>,
	Florian Schirmer <jolt@...box.org>,
	Felix Fietkau <nbd@...nwrt.org>, Michael Buesch <mb@...sch.de>
Subject: Re: [Bugme-new] [Bug 38102] New: BUG kmalloc-2048: Poison overwritten

On Tue, Jul 5, 2011 at 08:38, Eric Dumazet <eric.dumazet@...il.com> wrote:
> Le mardi 05 juillet 2011 à 08:29 +0400, Alexey Zaytsev a écrit :
>> On Tue, Jul 5, 2011 at 08:25, Eric Dumazet <eric.dumazet@...il.com> wrote:
>> > Le mardi 05 juillet 2011 à 08:17 +0400, Alexey Zaytsev a écrit :
>> >> >
>> >> Check out starting at packet 302893. 383 _identical_ ACKs were sent
>> >> out by the b44 machine within 30 milliseconds.
>> >
>> >
>> > As I said, b44 driver lost at least 200 consecutive frames (source says
>> > recovery takes about 20 ms)
>> >
>> > TCP then do its normal job.
>> >
>>
>> From my understanding, after a frame is lost, TCP would be waiting for
>> a retransmit. Or at least, it would not be sending 400 duplicate ACKs
>> for the single last frame received, right? Let me run tcpdump on the
>> b44 side now. I'm quite sure I won't see any ACK dups leaving the
>> stack.
>
> Wow, I believe you are on a wrong track. Honestly.
>
> Try to unpplug the wire for 100ms, and watch your "duplicate acks
> disease".
>
> Thats exactly what is happening with b44 driver doing a "fast recovery"
> right now.
>
> Thats a moot point. Running tcpdump on your b44 machine will kill your
> performance even more, it wont solve the b44 bug.
>
> If you prefer to 'fix tcp', please open another thread.

Ran tcpdump. You are right, I was wrong. Sorry for the noise.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html