[PATCH] ar: Check whether ar header values fit.

Mark Wielaard mark@klomp.org
Wed Sep 20 18:46:00 GMT 2017


On Fri, 2017-09-15 at 13:14 +0200, Mark Wielaard wrote:
> When compiling with -O3 gcc finds an interesting error:
> 
> src/ar.c: In function ‘do_oper_insert’:
> src/ar.c:1077:56: error: ‘%-*ld’ directive output may be truncated
> writing between 6 and 10 bytes into a region of size 7 [-
> Werror=format-truncation=]
>    snprintf (tmpbuf, sizeof (tmpbuf), ofmt ? "%-*lo" : "%-*ld",
> bufsize, val);
>                                                         ^~~~~
> The problem is that the ar header values have to fit in a limited
> (not zero terminated) string. We should check the snprintf return
> value to see if the values are representable.
> 
> Also make ar valgrind and ubsan clean and add a minimal sanity test.

I pushed this to master.



More information about the Elfutils-devel mailing list