Re: PATCH: cdrecord: avoiding scsi device numbering for ide devices

Adam Sampson
2004-08-23T12:22:34Z

Alan Cox <alan@lxorguk.ukuu.org.uk> writes:

>> Regarding the current 2.6.8 kernel, wouldn't it be a better idea to
>> move the CAP_SYS_RAWIO check to open time instead of when the ioctl is
>> called?
> This leads to all sorts of bugs where descriptors owned by one process
> are given to another less priviledged one.

Yes, but that's a class of bugs that are pretty well understood these
days; handing privileged FDs around is a moderately common and
pleasantly fine-grained way of doing things. Closing an FD is at least
as easy as dropping a capability, which is what you'd have to do
with the current scheme upon entering unprivileged code.

Besides, setuid CD-recording tools already have to worry about closing
unsafe FDs when they drop privileges, so this doesn't seem to add any
new security holes...

Thanks,

--
Adam Sampson <azz@us-lot.org> <http://offog.org/>