Messages in this thread | | | Subject | Re: Out of tree module using LSM | From | Jon Masters <> | Date | Thu, 29 Nov 2007 13:38:28 -0500 |
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On Thu, 2007-11-29 at 11:19 -0700, Justin Banks wrote: > Ray Lee wrote > > On Nov 29, 2007 9:45 AM, Greg KH <greg@kroah.com> wrote: > > > > Perhaps if you looked at this outside of a file-server scenario, the > > > > problem would be clearer? Anti-malware companies want to check > > > > anything written to disk on a system, either at write time or blocking > > > > the open/mmap. That means proactively protecting email programs with > > > > known vulnerabilities that have yet to be patched, web browsers > > > > writing and reading their caches, an Apache instance running WebDAV, > > > > the list goes on. And these are on desktop systems, with no attached > > > > file/network server. > > > > > > Ok, if they want to check on every open/mmap then just hook in glibc to > > > do this. Especially as they want to run userspace code at this point in > > > time. > > > > Doesn't help statically linked binaries, or anything else that bypases glibc. > > Or NFS servers for that matter, either.
Right. I threw all of these examples out there and was given the impression that a one-size fits all "solution" is needed. And to be honest, I can understand that desire.
I don't want to fall into any "snake oil" traps, because I know the reality is that there are holes in any solution. The only way to /really/ be sure of file integrity is to mark every user-visible pagecache page read only, trap on every single write, and re-scan the entirety of the file at that point. And even more silliness.
A compromise is therefore called for. I will go shut up and go talk to these guys and see if I can hook up a public discussion around a set of requirements. Preferably some code too, but at least a requirements doc.
Thanks,
Jon.
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