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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Shan Wei <shanwei@cn.fujitsu.com>
Cc: "Марк Коренберг" <socketpair@gmail.com>,
	"David Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org
Subject: Re: Fwd: Simple kernel attack using socketpair. easy, 100% reproductiblle, works under guest. no way to protect :(
Date: Fri, 26 Nov 2010 09:22:28 +0100	[thread overview]
Message-ID: <1290759748.2855.4.camel@edumazet-laptop> (raw)
In-Reply-To: <4CEF64A4.5080802@cn.fujitsu.com>

Le vendredi 26 novembre 2010 à 15:41 +0800, Shan Wei a écrit :
> Eric Dumazet wrote, at 11/25/2010 10:11 PM:
> > @@ -1845,6 +1871,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
> >  		unix_state_lock(sk);
> >  		skb = skb_dequeue(&sk->sk_receive_queue);
> >  		if (skb == NULL) {
> > +			unix_sk(sk)->recursion_level = 0;
> 
> For SOCK_SEQPACKET type, no need to clear recursion_level counter?
>  
> 

There is no need actually to clear it at all.

If an application has a complex setup with a dependence tree of unix
sockets, it will break if messages are not read fast enough.

So, maybe I should remove this line so that underlying problem comes
into surface immediately, rather than while in stress load.




  reply	other threads:[~2010-11-26  8:22 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <AANLkTikCeddPFRGojPGuB6oq3xGYgovtm8r4=WhjEDpe@mail.gmail.com>
2010-11-25  6:28 ` Simple kernel attack using socketpair. easy, 100% reproductiblle, works under guest. no way to protect :( Eric Dumazet
2010-11-25  6:52   ` Марк Коренберг
     [not found]     ` <1290668246.2798.93.camel@edumazet-laptop>
     [not found]       ` <AANLkTinQa8BCH-k0m=ndu4u8L-kCiD00jYjKvsvoxK2E@mail.gmail.com>
2010-11-25  7:52         ` Fwd: " Марк Коренберг
2010-11-25  8:16           ` Eric Dumazet
2010-11-25  8:35             ` Марк Коренберг
2010-11-25 14:11               ` Eric Dumazet
2010-11-26  4:38                 ` Shan Wei
2010-11-26  6:23                   ` Eric Dumazet
2010-11-26  7:52                     ` Shan Wei
2010-11-26  7:41                 ` Shan Wei
2010-11-26  8:22                   ` Eric Dumazet [this message]
2010-11-26  8:59                     ` Eric Dumazet
2010-11-29 17:46                 ` David Miller
2010-11-29 18:01                   ` Eric Dumazet
     [not found]       ` <AANLkTinRhmiVoVR5ibWOKe-OhY4fYUs_PHSATjxMGqg9@mail.gmail.com>
     [not found]         ` <1290670889.2798.127.camel@edumazet-laptop>
2010-11-25  8:05           ` Марк Коренберг
2010-11-25  7:14   ` Eric Dumazet

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