linux-kernel - Re: [PATCH 0/4] coredump: core dump masking support v3

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]

Message-ID: <20070224113916.GA9378@atrey.karlin.mff.cuni.cz>
Date:	Sat, 24 Feb 2007 12:39:16 +0100
From:	Pavel Machek <pavel@....cz>
To:	Markus Gutschke <markus@...gle.com>
Cc:	"Kawai, Hidehiro" <hidehiro.kawai.ez@...achi.com>,
	Andrew Morton <akpm@...l.org>,
	kernel list <linux-kernel@...r.kernel.org>,
	Robin Holt <holt@....com>, dhowells@...hat.com,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	sugita <yumiko.sugita.yf@...achi.com>,
	Satoshi OSHIMA <soshima@...hat.com>
Subject: Re: [PATCH 0/4] coredump: core dump masking support v3

> Kawai, Hidehiro wrote:
> >This patch series is version 3 of the core dump masking feature,
> >which provides a per-process flag not to dump anonymous shared
> >memory segments.
> 
> I just wanted to remind you that you need to be careful about dumping 
> the [vdso] segment no matter whether you omit other segments. I didn't 
> actually try running your patches, and if the kernel doesn't actually 
> consider this segment anonymous and shared, things might already work 
> fine as is.
> 
> In any case, you can check with "readelf -a", if the [vdso] segment is 
> there. And you will find that if you forget to dump it, "gdb" can no 
> longer give you stack traces on call chains that involve signal handlers.
> 
> As an alternative to your kernel patch, you could achieve the same goal 
> in user space, by linking my coredumper 
> http://code.google.com/p/google-coredumper/ into your binaries and 
> setting up appropriate signal handlers. An equivalent patch for 
> selectively omitting memory regions would be trivial to add. While this 
> does give you more flexibility, it of course has the drawback of 
> requiring you to change your applications, so there still is some 
> benefit in a kernelspace solution.

"We are too lazy to change 0.01% of apps that actually need it" is not
good enough reason to push the feature into kernel, I'd say.

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/