Messages in this thread | | | Date | Fri, 3 Jun 2011 13:37:26 -0500 | From | Scott Wood <> | Subject | Re: [PATCH] lib: introduce strdup_from_user |
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On Fri, 3 Jun 2011 21:26:21 +0300 Alexey Dobriyan <adobriyan@gmail.com> wrote:
> On Fri, Jun 3, 2011 at 9:22 PM, Timur Tabi <timur@freescale.com> wrote: > > Alexey Dobriyan wrote: > >> NAK > >> It accesses userspace data twice. > > > > What's wrong with that? > > If mm is shared, data can or will change under you. > > > How else is it supposed to know how much to allocate > > without using strlen first? > > I don't know. > What I know is that your function doesn't guarantee NUL-termination.
If the only issue is NUL-termination (and I think that's the only issue, everything else is userspace shooting itself in the foot), just stick "str[len] = 0" at the end.
-Scott
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