From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f41.google.com (mail-pb0-f41.google.com [209.85.160.41]) by kanga.kvack.org (Postfix) with ESMTP id 911CC6B0036 for ; Mon, 7 Oct 2013 12:22:53 -0400 (EDT) Received: by mail-pb0-f41.google.com with SMTP id rp2so7363352pbb.0 for ; Mon, 07 Oct 2013 09:22:53 -0700 (PDT) Received: by mail-wi0-f179.google.com with SMTP id hm2so5138165wib.12 for ; Mon, 07 Oct 2013 09:22:48 -0700 (PDT) MIME-Version: 1.0 Date: Mon, 7 Oct 2013 18:22:48 +0200 Message-ID: Subject: Deadlock (un-killable processes) in sys_futex From: =?UTF-8?B?Um9iZXJ0IMWad2nEmWNraQ==?= Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org After fuzzing the linux kernel (3.12-rc4) I have two processes which are stuck in an un-killable state. This is not specific to 3.12-rc4, as I'm able to reproduce it on most modern kernels (e.g. Ubuntu's 3.5) after a few minutes of fuzzing with a syscall fuzzer. The debug data can be found here: http://alt.swiecki.net/linux/20327/ - process PIDs: 20327 and 13735 It includes.. ftrace report (probably the most useful): I'm not expert in this kernel area (futex/mm), but it seems like a constatnt loop between fault_in_user_writeable() and do_page_fault(): http://alt.swiecki.net/linux/20327/20327.trace.report.txt /proc/pid/maps, /proc/pid/status: http://alt.swiecki.net/linux/20327/20327.maps.txt http://alt.swiecki.net/linux/20327/20327.status.txt kdb stacktraces showing that both processes (single-threaded) are stuck in sys_futex: http://alt.swiecki.net/linux/20327/20327.kdb.txt http://alt.swiecki.net/linux/20327/13735.kdb.txt kgdb stacktraces displaying rather corrupted data: http://alt.swiecki.net/linux/20327/20327.kgdb.txt http://alt.swiecki.net/linux/20327/13735.kgdb.txt kernel conf: http://alt.swiecki.net/linux/20327/config-3.12-rc4.txt --=20 Robert =C5=9Awi=C4=99cki -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org