Re: [PATCH] menuconfig: fix NULL pointer dereference when searching a symbol

[Libo Chen <clbchenlibo.chen@huawei.com>]

On 2013/5/7 10:40, Li Zefan wrote:
> Searching PPC_EFIKA results segmentation fault, and it's because
> get_symbol_prop() returns NULL.
> 
> In this case CONFIG_PPC_EFIKA is defined in arch/powerpc/platforms/
> 52xx/Kconfig, so it won't be parsed if ARCH!=PPC, but menuconfig
> knows this symbol when it parses sound/soc/fsl/Kconfig:
> 
> config SND_MPC52xx_SOC_EFIKA
>         tristate "SoC AC97 Audio support for bbplan Efika and STAC9766"
>         depends on PPC_EFIKA
> 
> This bug was introduced by commit bcdedcc1afd6 ("menuconfig: print more
> info for symbol without prompts").


It works!

Tested-by: Libo Chen <libo.chen@huawei.com>

> 
> Reported-by: Borislav Petkov <bp@alien8.de>
> Signed-off-by: Li Zefan <lizefan@huawei.com>
> ---
>  scripts/kconfig/menu.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
> index 826da66..b5c7d90 100644
> --- a/scripts/kconfig/menu.c
> +++ b/scripts/kconfig/menu.c
> @@ -600,14 +600,18 @@ void get_symbol_str(struct gstr *r, struct symbol *sym,
>  	}
>  	for_all_prompts(sym, prop)
>  		get_prompt_str(r, prop, head);
> +
>  	prop = get_symbol_prop(sym);
> -	str_printf(r, _("  Defined at %s:%d\n"), prop->menu->file->name,
> -		prop->menu->lineno);
> -	if (!expr_is_yes(prop->visible.expr)) {
> -		str_append(r, _("  Depends on: "));
> -		expr_gstr_print(prop->visible.expr, r);
> -		str_append(r, "\n");
> +	if (prop) {
> +		str_printf(r, _("  Defined at %s:%d\n"), prop->menu->file->name,
> +			prop->menu->lineno);
> +		if (!expr_is_yes(prop->visible.expr)) {
> +			str_append(r, _("  Depends on: "));
> +			expr_gstr_print(prop->visible.expr, r);
> +			str_append(r, "\n");
> +		}
>  	}
> +
>  	hit = false;
>  	for_all_properties(sym, prop, P_SELECT) {
>  		if (!hit) {
>