linux-kernel - Re: ipc,sem: sysv semaphore scalability

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:	Fri, 29 Mar 2013 11:43:25 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Dave Jones <davej@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Rik van Riel <riel@...riel.com>,
	Davidlohr Bueso <davidlohr.bueso@...com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	hhuang@...hat.com, "Low, Jason" <jason.low2@...com>,
	Michel Lespinasse <walken@...gle.com>,
	Larry Woodman <lwoodman@...hat.com>,
	"Vinod, Chegu" <chegu_vinod@...com>,
	Peter Hurley <peter@...leysoftware.com>,
	Stanislav Kinsbursky <skinsbursky@...allels.com>
Subject: Re: ipc,sem: sysv semaphore scalability

On Fri, Mar 29, 2013 at 9:17 AM, Dave Jones <davej@...hat.com> wrote:
>
> Now that I have that reverted, I'm not seeing msgrcv traces any more, but
> I've started seeing this..
>
> general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC

Do you have CONFIG_CHECKPOINT_RESTORE enabled? Does it go away if you
disable it?

I think I foud at least one bug in the MSG_COPY stuff: it leaks the
"copy" allocation if

    mode == SEARCH_LESSEQUAL

but maybe I'm misreading it. And that shouldn't cause the problem you
see, but it's indicative of how badly tested and thought through the
MSG_COPY code is.

Totally UNTESTED leak fix appended. Stanislav?

                     Linus

Download attachment "patch.diff" of type "application/octet-stream" (626 bytes)