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From: David Miller <davem@davemloft.net>
To: amit.salecha@qlogic.com
Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org,
	ameen.rahman@qlogic.com, anirban.chakraborty@qlogic.com
Subject: Re: [PATCH] qlcnic: dont assume NET_IP_ALIGN is 2
Date: Tue, 21 Sep 2010 12:33:38 -0700 (PDT)	[thread overview]
Message-ID: <20100921.123338.71122967.davem@davemloft.net> (raw)
In-Reply-To: <99737F4847ED0A48AECC9F4A1974A4B80F86F80278@MNEXMB2.qlogic.org>

From: Amit Salecha <amit.salecha@qlogic.com>
Date: Tue, 21 Sep 2010 03:41:42 -0500

>> So in order to improve "throughput", you were allowing for memory
>> exhaust and freeze of the _machine_ ?
>>
> This won't lead to such problem. truesize is used for accounting only.

Yes, it will.

Do you understand that we enforce both socket-level and system-wide
networking buffer usage in the stack?  And this limiting is based
upon skb->truesize and therefore only works if skb->truesize is
accurate?

It's meant to keep people from attacking a server and consuming large
percentages of system memory with networking buffer memory such that
other tasks cannot complete successfully.

And by mis-reporting the truesize you are subverting that entirely.

This qlcnic truesize bug is a huge security hole, can't you see this
now?


  parent reply	other threads:[~2010-09-21 19:33 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-17  5:14 [PATCHv2 NEXT 0/5]qlcnic: vlan rx accleration support Amit Kumar Salecha
2010-09-17  5:14 ` [PATCHv2 NEXT 1/5] qlcnic: support vlan rx accleration Amit Kumar Salecha
2010-09-17  5:29   ` Eric Dumazet
2010-09-17  9:57   ` [PATCH] qlcnic: dont assume NET_IP_ALIGN is 2 Eric Dumazet
2010-09-17 10:53     ` Amit Salecha
2010-09-18  5:58     ` David Miller
2010-09-20 11:16     ` Amit Salecha
2010-09-20 12:18       ` Eric Dumazet
2010-09-20 12:28         ` [PATCH net-next-2.6] qlnic: dont set skb->truesize Eric Dumazet
2010-09-20 17:09           ` David Miller
2010-09-20 15:58       ` [PATCH] qlcnic: dont assume NET_IP_ALIGN is 2 David Miller
2010-09-21  8:19         ` Amit Salecha
2010-09-21  8:34           ` Eric Dumazet
2010-09-21  8:41             ` Amit Salecha
2010-09-21  9:23               ` Eric Dumazet
2010-09-21 19:33               ` David Miller [this message]
2010-09-21 19:55                 ` [PATCH] netxen: dont set skb->truesize Eric Dumazet
2010-09-21 20:04                   ` David Miller
2010-09-17  5:14 ` [PATCHv2 NEXT 2/5] qlcnic: vlan gro support Amit Kumar Salecha
2010-09-17 18:24   ` David Miller
2010-09-17 18:25     ` David Miller
2010-09-17  5:14 ` [PATCHv2 NEXT 3/5] qlcnic: vlan lro support Amit Kumar Salecha
2010-09-17  5:14 ` [PATCHv2 NEXT 4/5] qlcnic: remove fw version check Amit Kumar Salecha
2010-09-17  5:14 ` [PATCHv2 NEXT 5/5] qlcnic: update version 5.0.10 Amit Kumar Salecha
2010-09-17 18:31 ` [PATCHv2 NEXT 0/5]qlcnic: vlan rx accleration support David Miller

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