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From: "H. Peter Anvin" <hpa@zytor.com>
To: Benjamin LaHaise <bcrl@redhat.com>
Cc: Andrew Morton <akpm@zip.com.au>,
	Linus Torvalds <torvalds@transmeta.com>,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: [patch] printk from userspace
Date: Tue, 13 Aug 2002 21:00:38 -0700	[thread overview]
Message-ID: <3D59D5E6.1010608@zytor.com> (raw)
In-Reply-To: 20020813235803.A15947@redhat.com

Benjamin LaHaise wrote:
> On Tue, Aug 13, 2002 at 08:18:18PM -0700, Andrew Morton wrote:
> 
>>The patch allows userspace to issue printk's, via sys_syslog():
> 
> 
> This is an incredibly bad idea.  It has security hole written all over it.  
> Any user can now spam the kernel's log ringbuffer and overrun potentially 
> important messages.
> 

First of all, only CAP_SYS_ADMIN.  As far as spamming the ring buffer, 
that's trivial to do today by just sending a bunch of bad network 
packets, or attaching a USB CD-ROM without a disc in the drive (yes, 
really... on my wife's laptop it was so bad that unless she unplugged 
the CD-ROM syslogd was eating her system alive), or...

	-hpa



  reply	other threads:[~2002-08-14  3:57 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-08-14  3:18 [patch] printk from userspace Andrew Morton
2002-08-14  3:58 ` Benjamin LaHaise
2002-08-14  4:00   ` H. Peter Anvin [this message]
2002-08-14  4:05     ` Benjamin LaHaise
2002-08-14  4:10   ` Alexander Viro
2002-08-14  4:11   ` Andrew Morton
2002-08-14  4:07     ` Benjamin LaHaise
2002-08-14  4:20       ` Alexander Viro
2002-08-14  4:26         ` Linus Torvalds
2002-08-14  4:35           ` Benjamin LaHaise
2002-08-14  4:42             ` H. Peter Anvin
2002-08-14  4:44             ` Linus Torvalds
2002-08-14  4:44               ` H. Peter Anvin
2002-08-14  4:48               ` Benjamin LaHaise
2002-08-14  4:58             ` Andrew Morton
2002-08-14  5:32               ` H. Peter Anvin
2002-08-19 11:28                 ` Daniel Phillips
2002-08-14  7:59           ` Miquel van Smoorenburg
2002-08-14 16:12             ` serial console (was Re: [patch] printk from userspace) Arkadiusz Miskiewicz
2002-08-15 12:43               ` Miquel van Smoorenburg
2002-08-14  4:33         ` [patch] printk from userspace H. Peter Anvin

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