Re: CVS commit: src/lib/libc/gen

[coypu]

On Sun, Feb 12, 2017 at 05:37:49PM -0500, Christos Zoulas wrote:
> Module Name:  src
> Committed By: christos
> Date:         Sun Feb 12 22:37:49 UTC 2017
> 
> Modified Files:
>       src/lib/libc/gen: vis.c
> 
> Log Message:
> fix off-by-one, found by asan.
> 

It fails in another case, attached

ASan is wrong about where the problem happens,
so I ran it in gdb - it's here:

514         for (start = dst; len > 0; len--) {
515                 c = *src++;
516                 dst = (*f)(dst, c, flags, len >= 1 ? *src : L'\0', extra);

breakpoint on do_svis

/* gcc -fsanitize=address -lasan asan.c && ./a.out */
#include <errno.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <vis.h>
#include <wchar.h>

static void
h_mbtowc(const char *locale, const char *legal)
{
        char buf[64];

        setlocale(LC_ALL, "C");
        setlocale(LC_CTYPE, locale);

        /* re-initialize internal state */
        mbtowc(NULL, NULL, 0);

        /* valid multibyte sequence case */
        (void)strvis(buf, legal, VIS_WHITE | VIS_OCTAL);
}

int main()
{
        h_mbtowc("zh_TW.eucTW", "\241\241");
}