linux-kernel - Re: SLUB: Return ZERO_SIZE

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: <ada6463llgr.fsf@cisco.com>
Date:	Mon, 04 Jun 2007 09:43:00 -0700
From:	Roland Dreier <rdreier@...co.com>
To:	"Pekka Enberg" <penberg@...helsinki.fi>
Cc:	"Linus Torvalds" <torvalds@...ux-foundation.org>,
	"Christoph Lameter" <clameter@....com>,
	"Andrew Morton" <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, jeremy@...p.org
Subject: Re: SLUB: Return ZERO_SIZE_PTR for kmalloc(0)

 > Then we might as well return your regular NULL pointer for zero-length
 > allocations as you can't do anything sane with ZERO_SIZE_PTR either.

No, because as was mentioned earlier in the thread, we want code to be
able to handle 0-sized allocations without special cases.  The goal is
that code like

	buf = kmalloc(nobj * obj_size);
	if (buf == NULL)
		return -ENOMEM;

should work fine if nobj happens to be 0.  But we do want to get an
oops if the code actually tries to read or write *buf.

 - R.
-
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/