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From: "René Scharfe" <l.s.r@web.de>
To: Andreas Schwab <schwab@linux-m68k.org>
Cc: Git List <git@vger.kernel.org>, Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH] apply: use strcmp(3) for comparing strings in gitdiff_verify_name()
Date: Sat, 8 Jul 2017 13:43:02 +0200	[thread overview]
Message-ID: <e46a7de9-3e0e-4eeb-c9a3-a8b5f22620b4@web.de> (raw)
In-Reply-To: <87tw2ngp94.fsf@linux-m68k.org>

Am 08.07.2017 um 13:08 schrieb Andreas Schwab:
> On Jul 08 2017, René Scharfe <l.s.r@web.de> wrote:
> 
>> Avoid running over the end of another -- a C string whose length we
>> don't know -- by using strcmp(3) instead of memcmp(3) for comparing it
>> with another C string.
> 
> That's not a good justification for the change, since memcmp never reads
> past the differing characters.

Interesting.  Where does that guarantee come from?

ASan reports an overflow with the following test program for me on
Debian testing x64:

#include <string.h>

int main(int argc, char **argv)
{
         char a[32] = "1234567890123456789012345678901";
         char b[2] = "a";
         return memcmp(a, b, 32);
}

  reply	other threads:[~2017-07-08 11:43 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-08  8:58 [PATCH] apply: use strcmp(3) for comparing strings in gitdiff_verify_name() René Scharfe
2017-07-08 11:08 ` Andreas Schwab
2017-07-08 11:43   ` René Scharfe [this message]
2017-07-08 13:38     ` Andreas Schwab
2017-07-09 12:20       ` René Scharfe
2017-07-09 12:37         ` Andreas Schwab
2017-07-09 13:19           ` René Scharfe
2017-07-09 17:05             ` Junio C Hamano
2017-07-08 11:08 ` Ramsay Jones
2017-07-08 11:52   ` René Scharfe
2017-07-08 22:29     ` Junio C Hamano
2017-07-09 12:20       ` René Scharfe

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