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-next>] [day] [month] [year] [list]
Message-ID: <20070812141905.4ee423b9@the-village.bc.nu>
Date:	Sun, 12 Aug 2007 14:19:05 +0100
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	WU Fengguang <wfg@...l.ustc.edu.cn>
Cc:	Balbir Singh <balbir@...ux.vnet.ibm.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [BUGFIX] NULL pointer dereference in __vm_enough_memory()

> > Great! So the problem might have existed for some time, but we never
> > saw it due to default over commit values? Were you using these values
> > for over commit even before?
> 
> No I changed it several weeks ago to stop my desktop from freezing.
> So yes, the bug may have been there for a while.

The bug is the new exec with lots of arguments code. It tries to insert a
vm struct without having a valid current->mm. That isn't permitted and
never had been (which is also why it broke the sparc mmu code etc).

You'll need to change the kernel security interface a little to make this
fly - I think the following should do it.

	- make __vm_enough_memory take a struct mm pointer and use it
	- make security_ops pass the extra current->mm
	- add a vm_enough_memory_mm security op
	- use security_vm_enough_memory_mm(mm, ...) in __insert_vm_struct

I'll knock up a quick patch and see what is needed (someone else can do
the selinux changes)
-
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ