Messages in this thread |  | | | Date | Mon, 28 Feb 2011 12:51:33 +0300 | | From | Vasiliy Kulikov <> | | Subject | Re: [PATCH] don't allow CAP_NET_ADMIN to load non-netdev kernel modules |
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On Mon, Feb 28, 2011 at 12:29 +0300, Michael Tokarev wrote: > 27.02.2011 23:22, Arnd Bergmann wrote: > > The backwards compatibility should mostly be for systems that today don't > > use split capabilities, right? > > > > The fallback could therefore rely on CAP_SYS_MODULE as well: > > > > if (request_module("netdev-%s", name)) { > > if (capable(CAP_SYS_MODULE)) > > request_module("%s", name); > > } > > > > Not 100% solution, but should solve the capability escalation nicely without > > causing much pain. > > To me this looks like the best solution so far - trivial and > compatible.
Agreed, it's looks good. But before the request_module() there is a check for capabile(CAP_NET_ADMIN), IMO it's better to request either CAP_NET_ADMIN or CAP_SYS_MODULE, not both of them.
if (!dev) { if (capable(CAP_NET_ADMIN)) request_module("netdev-%s", name)) if (capable(CAP_SYS_MODULE) { if (!request_module("%s", name)) WARN_ONE(1, "Loading kernel module for a network device" " with CAP_SYS_MODULE (deprecated). Use CAP_NET_ADMIN and alias" " netdev-%s instead\n", name); } } The only drawback is distributions/setups that already use CAP_SYS_MODULE'less network scripts.
David, are you OK with this way?
Thanks,
-- Vasiliy Kulikov http://www.openwall.com - bringing security into open computing environments
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