On Tue, Mar 15, 2011 at 07:50 -0400, James Bottomley wrote: > 1. Did anyone actually check for capabilities before assuming world > writeable files were wrong? I didn't check all these files as I haven't got these hardware :-) But as I can "chmod a+w" all sysfs files on my machine and they all become sensible to nonroot writes, I suppose there is nothing preventing nonroot users from writing to these buggy sysfs files. As you can see, there are no capable() checks in these drivers in open() or write(). > 2. Even if there aren't any capabilities checks in the implementing > routines, should there be (are we going the separated > capabilities route vs the monolithic root route)? IMO, In any case old good DAC security model must not be obsoleted just because someone thinks that MAC or anything else is more convenient for him. If sysfs is implemented via filesystem then it must support POSIX permissions semantic. MAC is very good in _some_ cases, but not instead of DAC. Thanks, -- Vasiliy Kulikov http://www.openwall.com - bringing security into open computing environments -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
