netdev - Re: Fwd: Simple kernel attack using socketpair. easy, 100% reproductiblle, works under guest. no way to protect :(

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]

Date:	Thu, 25 Nov 2010 13:35:30 +0500
From:	Марк Коренберг 
	<socketpair@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	netdev@...r.kernel.org
Subject: Re: Fwd: Simple kernel attack using socketpair. easy, 100%
 reproductiblle, works under guest. no way to protect :(

quick and dirty fix will be not to allow to pass unix socket inside
unix socket. I think it would not break much applications.

2010/11/25 Eric Dumazet <eric.dumazet@...il.com>:
> Le jeudi 25 novembre 2010 à 12:52 +0500, Марк Коренберг a écrit :
>> ---------- Forwarded message ----------
>> From: Марк Коренберг <socketpair@...il.com>
>> Date: 2010/11/25
>> Subject: Re: Simple kernel attack using socketpair. easy, 100%
>> reproductiblle, works under guest. no way to protect :(
>> To: Eric Dumazet <eric.dumazet@...il.com>
>>
>>
>> 2010/11/25 Eric Dumazet <eric.dumazet@...il.com>:
>> > Le jeudi 25 novembre 2010 à 11:52 +0500, Марк Коренберг a écrit :
>> >> Well, It seems, that patch likely will fix 100% CPU usage.
>> >>
>> >> But what about eating all available descriptors in kernel ? vulnerability ?
>> >>
>> >
>> > It doesnt fix cpu usage actually, your program eats 100% of one cpu,
>> > like the following one :
>> >
>> > for (;;) ;
>> >
>> > If you want not eat 100% cpu, I suggest you add some blocking calls,
>> > like usleep(10000)
>> >
>> > for (;;) usleep(10000);
>> >
>> > Patch only makes sure kernel wont eat too much memory to store inflight
>> > unix sockets.
>>
>> I have attached source which proove, that loop not inside this
>> program, but inside kernel.
>>
>> --
>
> Better send a fix, now that thousand of people know how to kill a linux
> machine.
>
> Congrats.
>
>
>
>



-- 
Segmentation fault
--
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