Re: SECURITY.NNOV: file locking and security (group policy DoS on Windows 2000 domain)

From: Seth Arnold (sarnold@wirex.com)
Date: 12/08/01 

Date: Fri, 7 Dec 2001 17:15:48 -0800
From: Seth Arnold <sarnold@wirex.com>
To: bugtraq@securityfocus.com

On Fri, Dec 07, 2001 at 11:57:58AM +0300, 3APA3A wrote:
> The way file locks interfere with file access depends on OS. There are 2
> possible situations: moderate and non-moderate file locks. *BSD and
> linux use non-moderate locking, while Windows NT locking is moderate.
> What does it mean? Under Unix file locking is only checked then another
> application tries to lock the file. If application doesn't use file
> locking it will not be affected by file locking.

3APA3A -- close....

A long-time feature of many Unix systems, including Linux (and probably
all the BSDs too, but I don't know this for sure) is mandatory file
locking, implemented in the kernel. It can be turned on using the setgid
bit on regular files.

Look for Documentation/mandatory.txt in the linux kernel source tree. It
has all the gory details on mandary file locking, as it is implemented
in the linux kernel. (Or, was implemented, in 1996.. :)

Cheers! 

-- 
People who separate manpages from the programs
they document would steal sheep.  -- apologies to Goudy

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