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From: Sasha Levin <sasha.levin@oracle.com>
To: Hannes Frederic Sowa <hannes@stressinduktion.org>,
	Eric Dumazet <eric.dumazet@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
	LKML <linux-kernel@vger.kernel.org>,
	netdev@vger.kernel.org, Andrey Ryabinin <a.ryabinin@samsung.com>,
	Dave Jones <davej@redhat.com>
Subject: Re: net: integer overflow in ip_idents_reserve
Date: Tue, 16 Dec 2014 20:15:12 -0500	[thread overview]
Message-ID: <5490D920.5000104@oracle.com> (raw)
In-Reply-To: <1418771356.3449499.203748285.4B1A82B8@webmail.messagingengine.com>

On 12/16/2014 06:09 PM, Hannes Frederic Sowa wrote:
> 
> On Tue, Dec 16, 2014, at 22:47, Eric Dumazet wrote:
>> > On Tue, 2014-12-16 at 16:19 -0500, Sasha Levin wrote:
>>> > > Hi Eric,
>>> > > 
>>> > > While fuzzing with trinity on a -next kernel with the undefined behaviour
>>> > > sanitizer path, I've observed the following warning in code which was
>>> > > introduced in 04ca6973f7 ("ip: make IP identifiers less predictable"):
>> > 
>> > This is a false positive.
> Also we compile the whole kernel with -fno-strict-overflow, so every
> report of signed overflow leading to undefined behavior is probably a
> false positive. I don't know if it is worth to try to get rid of them, I
> doubt it.

I reported this one because there's usually some code to handle overflow
in code that expects that and here there was none (I could see).

For example, the ntp code had a few cases where a user could generate
overflows and mess up quite a few things (he got what he asked for -
problems).


Thanks,
Sasha

  parent reply	other threads:[~2014-12-17  1:15 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-16 21:19 net: integer overflow in ip_idents_reserve Sasha Levin
2014-12-16 21:47 ` Eric Dumazet
2014-12-16 23:09   ` Hannes Frederic Sowa
2014-12-16 23:22     ` Eric Dumazet
2014-12-17  1:15     ` Sasha Levin [this message]
2014-12-17 14:11       ` Eric Dumazet

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