Re: [PATCH] of: overlay: Fix uninitialized vars in dup_and_fixup_symbol_prop()

From: Rob Herring
Date: Tue Sep 19 2017 - 13:28:05 EST


On Sun, Sep 10, 2017 at 12:26:04PM +0200, Geert Uytterhoeven wrote:
> With gcc 4.1.2:
>
> drivers/of/overlay.c: In function âdup_and_fixup_symbol_propâ:
> drivers/of/overlay.c:108: warning: âoverlay_name_lenâ may be used uninitialized in this function
> drivers/of/overlay.c:100: warning: âovinfoâ may be used uninitialized in this function
>
> Indeed, if ov->count == 0, both variables are uninitialized, which may
> lead to a crash when dereferencing ovinfo later.
>
> Currently this is a false positive, as the sole creator of of_overlay
> structures (of_build_overlay_info(), introduced in commit
> 7518b5890d8ac366 ("of/overlay: Introduce DT overlay support") checks for
> this.
>
> To prevent future issues, add a check for a zero ov->count to
> dup_and_fixup_symbol_prop(). Note that this does not get rid of the
> actual compiler warning.
>
> Fixes: d1651b03c2df75db ("of: overlay: add overlay symbols to live device tree")
> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
> drivers/of/overlay.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Applied.

Rob