Re: Is reallocarray() planned to be standardized?

From	cross@spitfire.i.gajendra.net (Dan Cross)
Newsgroups	comp.lang.c
Subject	Re: Is reallocarray() planned to be standardized?
Date	2026-05-15 22:32 +0000
Organization	PANIX Public Access Internet and UNIX, NYC
Message-ID	<10u86t2$2tm$2@reader1.panix.com> (permalink)
References	<10u5a5v$nagc$1@dont-email.me> <10u844d$i6t3$1@dont-email.me> <10u84el$in4$1@reader1.panix.com> <10u84o1$idnu$1@dont-email.me>

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In article <10u84o1$idnu$1@dont-email.me>,
Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>On 5/15/2026 2:50 PM, Dan Cross wrote:
>> In article <10u844d$i6t3$1@dont-email.me>,
>> Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>>> On 5/15/2026 4:02 AM, Dan Cross wrote:
>>>> In article <10u601c$uo0d$12@kst.eternal-september.org>,
>>>> Keith Thompson  <Keith.S.Thompson+u@gmail.com> wrote:
>>>>> [snip]
>>>>> As far as I can tell, reallocarray() differs from realloc() only
>>>>> in that it takes two arguments to specify the size, and fails
>>>>> if the multiplication would overflow (um, I mean wrap around).
>>>>> realloc(p, n*size) does the same thing in the absence of overflow.
>>>>> Obviously somebody thought it was worthwhile.
>>>>
>>>> It's a security thing, similar to `explicit_bzero` or
>>>> `memset_explicit`.
>>>
>>> Fwiw, iirc wrt security. Instead of filling it with 0's, you fill it
>>> with data from a TRNG. An attacker can look for parts that are zeros.
>> 
>> No.
>
>Iirc, a long time ago I kind of remember reading something about 
>overwrite sensitive data multiple times (e.g., the DoD 5220.22-M 
>standard for storage, though adapted for RAM), sometimes using a pass of 
>random data followed by a pass of fixed characters, or using a fast 
>CSPRNG (like ChaCha20) to generate fast pseudo-random bytes so they 
>don't deplete the physical TRNG.

Maybe on disks or SSDs or something.  Not in DRAM.

	- Dan C.

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Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-14 20:09 +0000
  Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-14 21:10 +0000
    Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-14 23:35 +0000
      Re: Is reallocarray() planned to be standardized? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-05-14 17:46 -0700
        Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-15 02:00 +0000
          Re: Is reallocarray() planned to be standardized? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-05-14 19:22 -0700
            Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-15 11:02 +0000
              Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-15 14:44 -0700
                Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-15 21:50 +0000
                Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-15 14:55 -0700
                Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-15 15:02 -0700
                Re: Is reallocarray() planned to be standardized? scott@slp53.sl.home (Scott Lurndal) - 2026-05-15 22:12 +0000
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-16 11:38 +0200
                Re: Is reallocarray() planned to be standardized? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-05-16 13:00 +0200
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-16 13:58 +0200
                Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-16 12:34 +0000
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-16 16:25 +0200
                Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-16 12:32 -0700
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-17 11:10 +0200
                Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-19 14:03 -0700
                Re: Is reallocarray() planned to be standardized? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-05-17 06:36 +0200
                Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-16 12:25 -0700
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-17 11:12 +0200
                Re: Is reallocarray() planned to be standardized? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-05-17 02:26 -0700
                Leader Keith has spoken! (Was: Is reallocarray() planned to be standardized?) gazelle@shell.xmission.com (Kenny McCormack) - 2026-05-17 12:54 +0000
                Re: Is reallocarray() planned to be standardized? scott@slp53.sl.home (Scott Lurndal) - 2026-05-17 19:19 +0000
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-17 21:53 +0200
                Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-17 20:30 +0000
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-18 08:14 +0200
                Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-17 20:01 +0000
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-18 09:13 +0200
                Re: Is reallocarray() planned to be standardized? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-05-18 09:51 +0200
                Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-18 14:34 +0000
                Re: Is reallocarray() planned to be standardized? David Brown <david.brown@hesbynett.no> - 2026-05-18 16:49 +0200
                Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-18 16:19 -0700
                Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-15 22:32 +0000
            Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-15 15:23 +0000
              Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-15 17:28 +0000
              Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-15 17:40 +0000
                Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-15 17:50 +0000
                Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-15 18:28 +0000
                Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-15 21:35 +0000
                Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-15 15:05 -0700
                Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-15 22:35 +0000
                Re: Is reallocarray() planned to be standardized? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-05-15 17:18 -0700
                Re: Is reallocarray() planned to be standardized? Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-05-16 08:07 +0000
                Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-16 12:44 +0000
                Re: Is reallocarray() planned to be standardized? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-05-15 23:44 +0200
                Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-15 21:47 +0000
                Re: Is reallocarray() planned to be standardized? scott@slp53.sl.home (Scott Lurndal) - 2026-05-15 22:10 +0000
                Re: Is reallocarray() planned to be standardized? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-05-16 01:13 +0200
                AIX (was Re: Is reallocarray() planned to be standardized?) cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-15 22:30 +0000
                Re: Is reallocarray() planned to be standardized? Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-05-16 08:04 +0000
    Re: Is reallocarray() planned to be standardized? Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-05-15 07:07 +0000
      Re: Is reallocarray() planned to be standardized? kalevi@kolttonen.fi (Kalevi Kolttonen) - 2026-05-15 13:58 +0000
        Re: Is reallocarray() planned to be standardized? Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-05-16 00:25 +0000
  Re: Is reallocarray() planned to be standardized? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-05-14 17:26 -0700
    Re: Is reallocarray() planned to be standardized? cross@spitfire.i.gajendra.net (Dan Cross) - 2026-05-15 02:08 +0000
  Re: Is reallocarray() planned to be standardized? Bonita Montero <Bonita.Montero@gmail.com> - 2026-05-16 11:28 +0200

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