linux-kernel - Re: [PATCH] kmsg: Use vmalloc instead of kmalloc when writing

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: <20120330153013.GC18488@kroah.com>
Date:	Fri, 30 Mar 2012 08:30:13 -0700
From:	Greg KH <gregkh@...uxfoundation.org>
To:	Sasha Levin <levinsasha928@...il.com>
Cc:	arnd@...db.de, viro@...iv.linux.org.uk, davej@...hat.com,
	tglx@...utronix.de, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] kmsg: Use vmalloc instead of kmalloc when writing

On Fri, Mar 30, 2012 at 01:04:27PM -0400, Sasha Levin wrote:
> There are no size checks in kmsg_write(), and we try allocating enough
> memory to store everything userspace gave us, which may be too much for
> kmalloc to allocate.

Really?  Have you seen this fail?  As only root can do this, is this
really a problem?

> One option would be to limit it to something, but we can't come up with
> a number that would make sense.
> 
> Instead, just use vmalloc so that nothing would break with large amounts
> of data.

Are you sure this will work properly?  Have you tested it with large
amounts of data?

thanks,

greg k-h
--
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/