Messages in this thread | | | Date | Thu, 27 Jun 2013 14:03:44 -0400 | From | Mathieu Desnoyers <> | Subject | Re: goldfish driver: Missing get_user_pages in goldfish_pipe_read_write() |
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* Greg Kroah-Hartman (gregkh@linuxfoundation.org) wrote: > On Thu, Jun 27, 2013 at 01:35:32PM -0400, Mathieu Desnoyers wrote: > > The following code snippet: > > > > drivers/platform/goldfish/goldfish_pipe.c: > > goldfish_pipe_read_write() > > > > /* Ensure that the corresponding page is properly mapped */ > > /* FIXME: this isn't safe or sufficient - use get_user_pages */ > > if (is_write) { > > char c; > > /* Ensure that the page is mapped and readable */ > > if (__get_user(c, (char __user *)address)) { > > if (!ret) > > ret = -EFAULT; > > break; > > } > > } else { > > /* Ensure that the page is mapped and writable */ > > if (__put_user(0, (char __user *)address)) { > > if (!ret) > > ret = -EFAULT; > > break; > > } > > } > > > > Seems to lack the kind of validation required to make it fail properly > > if the memory range is not fully populated. > > This is an emulated platform only, so it's probably not a big deal, > right?
You're probably right. As long as it is not configured and somehow still accessible on a production device.
> > > I see that this feature has been merged in Linux kernel 3.9, but the > > FIXME is still there in 3.10-rc7. Any plans on fixing this ? > > It would be good to get fixed, but probably way down on the priority > list.
Agreed,
Thanks,
Mathieu
> > thanks, > > greg k-h
-- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
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