linux-kernel - Re: [PATCH] fix quadratic behavior of shrink_dcache

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: <ee9e417a0702091623t1ccf55b8wb05b64b9c51474a6@mail.gmail.com>
Date:	Fri, 9 Feb 2007 19:23:31 -0500
From:	"Russ Cox" <rsc@...ch.com>
To:	"Andrew Morton" <akpm@...ux-foundation.org>
Cc:	"Miklos Szeredi" <miklos@...redi.hu>,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] fix quadratic behavior of shrink_dcache_parent()

> "The file system mounted on /tmp/z in the example contains 2^50
> directories".   heh.
>
> I do wonder how realistic this problem is in real life.

That's a fair concern, although I was trying this as part
of evaluating how much someone could hose a system
if we let them mount arbitrary FUSE servers.  And the
answer is: they could make it completely unusable,
requiring reboot.

I ran a later test that printed how deep it got into
the file tree and it was only a few hundred thousand
if I recall correctly.  A determined attacker might even
manage to do this in a normal file system.

But sure, it's not a common case.  ;-)

Russ
-
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/