Re: [PATCH] um: vector: Fix memory leak in vector_config

[Geert Uytterhoeven]

Hi Miaoqian,

On Tue, Jan 3, 2023 at 1:17 PM Miaoqian Lin <linmq006@xxxxxxxxx> wrote:
> On 2023/1/3 18:28, Anton Ivanov wrote:
> > On 03/01/2023 08:00, Geert Uytterhoeven wrote:
> >> On Thu, Dec 29, 2022 at 8:53 AM Miaoqian Lin <linmq006@xxxxxxxxx> wrote:
> >>> kstrdup() return newly allocated copy of the string.
> >>> Call kfree() to release the memory when after use.
> >>>
> >>> Fixes: 49da7e64f33e ("High Performance UML Vector Network Driver")
> >>> Signed-off-by: Miaoqian Lin <linmq006@xxxxxxxxx>
> >> Thanks for your patch!
> >>
> >>> --- a/arch/um/drivers/vector_kern.c
> >>> +++ b/arch/um/drivers/vector_kern.c
> >>> @@ -765,6 +765,7 @@ static int vector_config(char *str, char **error_out)
> >>>
> >>>          parsed = uml_parse_vector_ifspec(params);
> >>>
> >>> +       kfree(params);
> >> Are you sure the memory pointed to by "params" is no longer used?
> >> "parsed" seems to contain pointers pointing to (parts of) the string
> >> pointed to by "params", so it cannot be freed.
> >
> > +1.
> >
> > I was just about to send the same comment.
> >
> Oh yes, thanks for spotting this. We should only perform release when uml_parse_vector_ifspec() fails (returns NULL). In this situation, 'params' is no longer used. Do you agree?

Yes, that sounds fine to me.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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