From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: [PATCH 2/6] imap-send.c, cram: allocate enough memory for null terminated string Date: Tue, 29 Mar 2016 21:07:57 -0400 Message-ID: <20160330010756.GA2237@sigill.intra.peff.net> References: <1459298333-21899-1-git-send-email-sbeller@google.com> <1459298333-21899-3-git-send-email-sbeller@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: gitster@pobox.com, git@vger.kernel.org To: Stefan Beller X-From: git-owner@vger.kernel.org Wed Mar 30 03:08:06 2016 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1al4cA-0005hu-Aq for gcvg-git-2@plane.gmane.org; Wed, 30 Mar 2016 03:08:06 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753076AbcC3BIA (ORCPT ); Tue, 29 Mar 2016 21:08:00 -0400 Received: from cloud.peff.net ([50.56.180.127]:40460 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752674AbcC3BIA (ORCPT ); Tue, 29 Mar 2016 21:08:00 -0400 Received: (qmail 22629 invoked by uid 102); 30 Mar 2016 01:07:59 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.84) with SMTP; Tue, 29 Mar 2016 21:07:59 -0400 Received: (qmail 30131 invoked by uid 107); 30 Mar 2016 01:07:58 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.84) with SMTP; Tue, 29 Mar 2016 21:07:58 -0400 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 29 Mar 2016 21:07:57 -0400 Content-Disposition: inline In-Reply-To: <1459298333-21899-3-git-send-email-sbeller@google.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, Mar 29, 2016 at 05:38:49PM -0700, Stefan Beller wrote: > `strlen` returns the length of a string without the terminating null byte. > To make sure enough memory is allocated we need to pass `strlen(..) + 1` > to the allocation function. > > Signed-off-by: Stefan Beller > --- > imap-send.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/imap-send.c b/imap-send.c > index 2c52027..f7e9909 100644 > --- a/imap-send.c > +++ b/imap-send.c > @@ -872,7 +872,7 @@ static char *cram(const char *challenge_64, const char *user, const char *pass) > * enough upper bound for challenge (decoded result). > */ > encoded_len = strlen(challenge_64); > - challenge = xmalloc(encoded_len); > + challenge = xmalloc(encoded_len + 1); > decoded_len = EVP_DecodeBlock((unsigned char *)challenge, > (unsigned char *)challenge_64, encoded_len); > if (decoded_len < 0) Others pointed out that patches 1 and 2 here probably don't need the extra byte. But as a side note, for any cases that do, please use xmallocz() instead of manually adding 1 to the length. Even if you don't need the final byte to be NUL, it checks for integer overflow. -Peff