Date: Thu, 7 Aug 2008 11:28:00 +0200
From: Pavel Machek <pavel@suse.cz>
To: tvrtko.ursulin@sophos.com
Cc: Arjan van de Ven <arjan@infradead.org>,
       "Press, Jonathan" <Jonathan.Press@ca.com>, linux-kernel@vger.kernel.org,
       linux-security-module@vger.kernel.org, malware-list@lists.printk.net,
       Rik van Riel <riel@redhat.com>
Subject: Re: [malware-list] [RFC 0/5] [TALPA] Intro to a linuxinterfaceforon access scanning
Message-ID: <20080807092800.GA22222@atrey.karlin.mff.cuni.cz>
References: <20080806064418.6afa0672@infradead.org> <20080806141656.8B44B2FE94A@pmx1.sophos.com>
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Hi!

> Problems with inotify as far as I know:
> 
> You can't do something like inotify("/") (made up API) but you have to set 
> up a watch for every directory you wan't to watch. That seems like a waste 
> of resources.
> 
> Then you get back a file name, if you wan't to report it or attempt* to 
> scan it you have to build a pathname yourself, which means you have to 
> maintain the whole tree of names in memory. Even bigger waste.
> 
> When I say attempt to scan it above I mean that we are back into the 
> pathanme teritorry. It is not guaranteed we will be able to open and scan 
> using that pathname. I don't know what inotify reports with chroots and 
> private namespaces, but it can certainly fail with NFS and root_squash. So 
> it is less effective as well as being resource intensive.
> 
> I think this is a good amount of flaws which shows inotify isn't really 
> ideal.

Not ideal, but looks like good enough, and could certainly be
improved. If it is secure-enough for you (I think it is), that looks
like a way to go.

(Plus, such improvements would actually be very welcome).
									Pavel

-- 
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