[PATCH app/twm 1/2] When replacing a colormap, free old map, not new one

[Walter Harms]

> Alan Coopersmith <alan.coopersmith at oracle.com> hat am 30. September 2018 um
> 23:44 geschrieben:
> 
> 
> Found by Oracle's Parfait 2.2 static analyzer:
> 
> Error: Use after free
>    Use after free [use-after-free] (CWE 416):
>       Use after free of pointer Scr
>         at line 421 of src/util.c in function 'InsertRGBColormap'.
>         Invalid pointer accessible via global Scr at line 105 of src/twm.c
>           maps escapes to sc->maps at line 419 of src/util.c in function
> 'InsertRGBColormap'
>           maps freed with XFree at line 406
> 
> Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>
> ---
>  src/util.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/util.c b/src/util.c
> index 8e9dab9..e254cd5 100644
> --- a/src/util.c
> +++ b/src/util.c
> @@ -403,7 +403,7 @@ InsertRGBColormap (Atom a, XStandardColormap *maps, int
> nmaps, Bool replace)
>      }
>  
>      if (replace) {			/* just update contents */
> -	if (sc->maps) XFree (maps);
> +	if (sc->maps) XFree (sc->maps);

just
         XFree (sc->maps);

is sufficient

re,
 wh
 
>  	if (sc == Scr->StdCmapInfo.mru) Scr->StdCmapInfo.mru = NULL;
>      } else {				/* else appending */
>  	sc->next = NULL;
> -- 
> 2.15.2
> 
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