From: Theodore Ts'o Subject: Re: fuzz testing an ext4fs file system under a 32 bit Linux user mode linux guest let task jbd2/ubda hang Date: Sun, 3 Aug 2014 14:42:10 -0400 Message-ID: <20140803184210.GV24826@thunk.org> References: <53DE3E92.3060304@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-ext4@vger.kernel.org, UML devel To: Toralf =?iso-8859-1?Q?F=F6rster?= Return-path: Received: from imap.thunk.org ([74.207.234.97]:42408 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751562AbaHCSxK (ORCPT ); Sun, 3 Aug 2014 14:53:10 -0400 Content-Disposition: inline In-Reply-To: <53DE3E92.3060304@gmx.de> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Aug 03, 2014 at 03:52:18PM +0200, Toralf F=F6rster wrote: > Hello, >=20 > fuzzying a 32 bit stable Gentoo x86 linux with trinity (and without e= xcluding the munmap syscall but it might be independed from this) gives= within a 32 bit user mode linux guest : The problem with these sorts of trinity bug reports is that we have no idea which syscall or set of syscalls might have corrupted kernel state to the point where the kernel started malfunctioning. Sometimes, a trinity induced bug is obvious, when it causes a system call to immediately access an illegal memory location. But if it causes some more subtle corruption, possibly in a completely unrelated subsystem, figuring out what actually happened can be close to impossible. So there's not much I can do with this sort of bug report. If you can easily repeat it, and you can dump out the system call stream, we might be able to make a smaller reproduction case, at which point trying to debug this sort of failure would be tractable. Cheers, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html