linux-kernel - Re: [PATCH v1 RFC 6/6] crypto: implement KFuzzTest targets for PKCS7 and RSA parsing

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: <CANgxf6xCYE4dQQ9=UDotB351wxs46=ZUhWz4zfrROH5nNsSBRg@mail.gmail.com>
Date: Fri, 22 Aug 2025 10:15:51 +0200
From: Ethan Graham <ethan.w.s.graham@...il.com>
To: Marco Elver <elver@...gle.com>
Cc: Ignat Korchagin <ignat@...udflare.com>, Eric Biggers <ebiggers@...nel.org>, ethangraham@...gle.com, 
	glider@...gle.com, andreyknvl@...il.com, brendan.higgins@...ux.dev, 
	davidgow@...gle.com, dvyukov@...gle.com, jannh@...gle.com, rmoar@...gle.com, 
	shuah@...nel.org, tarasmadan@...gle.com, kasan-dev@...glegroups.com, 
	kunit-dev@...glegroups.com, linux-kernel@...r.kernel.org, linux-mm@...ck.org, 
	David Howells <dhowells@...hat.com>, Lukas Wunner <lukas@...ner.de>, 
	Herbert Xu <herbert@...dor.apana.org.au>, "David S. Miller" <davem@...emloft.net>, 
	"open list:HARDWARE RANDOM NUMBER GENERATOR CORE" <linux-crypto@...r.kernel.org>
Subject: Re: [PATCH v1 RFC 6/6] crypto: implement KFuzzTest targets for PKCS7
 and RSA parsing

On Tue, Aug 19, 2025 at 12:08 PM Marco Elver <elver@...gle.com> wrote:
> For example something like:
> For subsystem foo.c, define a KFuzzTest in foo_kfuzz.c, and then in
> the Makfile add "obj-$(CONFIG_KFUZZTEST) += foo_kfuzz.o".

I agree that fuzz targets should only be built if CONFIG_KFUZZTEST is
enabled. Building a separate foo_kfuzz.o is probably ideal, but will
need to think about how to cleanly handle static functions.

> Alternatively, to test internal static functions, place the KFuzzTest
> harness in a file foo_kfuzz.h, and include at the bottom of foo.c.
>
> Alex, Ethan, and KUnit folks: What's your preference?

I think placing fuzz targets in separate files is a step in the right
direction. Including a foo_kfuzz.h file inside of the source does still
pollute the file to some extent but certainly less than having one or
more KFuzzTest targets defined alongside the code.