linux-kernel - Re: [PATCH 09/30] mtd: Don't cast kmalloc() return value in drivers/mtd/maps/pmcmsp-flash.c

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <9a8748490708261510u6f373d2s760bef86e81bbe02@mail.gmail.com>
Date:	Mon, 27 Aug 2007 00:10:17 +0200
From:	"Jesper Juhl" <jesper.juhl@...il.com>
To:	"Jan Engelhardt" <jengelh@...putergmbh.de>
Cc:	"Denys Vlasenko" <vda.linux@...glemail.com>,
	"Robert P. J. Day" <rpjday@...dspring.com>,
	linux-mtd@...ts.infradead.org,
	"David Woodhouse" <dwmw2@...radead.org>,
	"Linux Kernel Mailing List" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 09/30] mtd: Don't cast kmalloc() return value in drivers/mtd/maps/pmcmsp-flash.c

On 26/08/07, Jan Engelhardt <jengelh@...putergmbh.de> wrote:
>
> On Aug 26 2007 15:28, Denys Vlasenko wrote:
> >> >
> >> > What exactely would using kcalloc() over kzalloc() here buy us?
> >>
> >> technically, nothing.
> >
> >The idea of calloc is that it can check for underflow in parameter.
>
> Actually, overflow.
>
> calloc(0xFFFF0000,  0x1000) => will return NULL
> malloc(0xFFFF0000 * 0x1000) => silent 32 bit multiplication/truncation,
> will allocate less than requested.
>
> >calloc(-1, 10000000) => easy to detect
> >malloc(-1 * 10000000) => malloc(-10000000) => not so trivial
>
Ok, that makes a bit of sense. Thank you.


-- 
Jesper Juhl <jesper.juhl@...il.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please      http://www.expita.com/nomime.html
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/