Re: AUDIT of 2.5.15 copy_to/from_user

David Woodhouse (dwmw2@infradead.org)
Sun, 19 May 2002 18:52:36 +0100

alan@lxorguk.ukuu.org.uk said:
> > On the emu10k1 driver we use access_ok(VERIFY_READ) once at the
> > beginning of the write() routine to check we can access the user buffer.
> > After that we always use __copy_from_user() and we trust it not to fail.
> > Is this correct, or not?

> This is correct

Even if another thread unmaps the page we were trying to read from between
the access_ok() and the actual copy?

--
dwmw2




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