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: <Pine.LNX.4.64.0708261635080.15614@fbirervta.pbzchgretzou.qr>
Date:	Sun, 26 Aug 2007 16:37:13 +0200 (CEST)
From:	Jan Engelhardt <jengelh@...putergmbh.de>
To:	Denys Vlasenko <vda.linux@...glemail.com>
cc:	"Robert P. J. Day" <rpjday@...dspring.com>,
	Jesper Juhl <jesper.juhl@...il.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 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


	Jan
-- 
-
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/