Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) client-ip=2620:137:e000::3:1;
MIME-Version: 1.0
References: <CA+fCnZePgv=V65t4FtJvcyKvhM6yA3amTbPnwc5Ft5YdzpeeRg@mail.gmail.com>
 <20230915024559.32806-1-haibo.li@mediatek.com> <CA+fCnZfuaovc4fk6Z+p1haLk7iemgtpF522sej3oWYARhBYYUQ@mail.gmail.com>
In-Reply-To: <CA+fCnZfuaovc4fk6Z+p1haLk7iemgtpF522sej3oWYARhBYYUQ@mail.gmail.com>
From:   Jann Horn <jannh@google.com>
Date:   Fri, 15 Sep 2023 19:04:00 +0200
Message-ID: <CAG48ez3GSubTFA8+hw=YDZoVHC79JVwNi+xFTQt9ssy_+O1aaw@mail.gmail.com>
Subject: Re: [PATCH] kasan:fix access invalid shadow address when input is illegal
To:     Andrey Konovalov <andreyknvl@gmail.com>
Cc:     Haibo Li <haibo.li@mediatek.com>, akpm@linux-foundation.org,
        angelogioacchino.delregno@collabora.com, dvyukov@google.com,
        glider@google.com, kasan-dev@googlegroups.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-mediatek@lists.infradead.org, linux-mm@kvack.org,
        mark.rutland@arm.com, matthias.bgg@gmail.com,
        ryabinin.a.a@gmail.com, vincenzo.frascino@arm.com,
        xiaoming.yu@mediatek.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Fri, Sep 15, 2023 at 6:51=E2=80=AFPM Andrey Konovalov <andreyknvl@gmail.=
com> wrote:
> On Fri, Sep 15, 2023 at 4:46=E2=80=AFAM 'Haibo Li' via kasan-dev
> <kasan-dev@googlegroups.com> wrote:
> >
> > The patch checks each shadow address,so it introduces extra overhead.
>
> Ack. Could still be fine, depends on the overhead.
>
> But if the message printed by kasan_non_canonical_hook is good enough
> for your use case, I would rather stick to that.
>
> > Now kasan_non_canonical_hook only works for CONFIG_KASAN_INLINE.
> >
> > And CONFIG_KASAN_OUTLINE is set in my case.
> >
> > Is it possible to make kasan_non_canonical_hook works for both
> > INLINE and OUTLINE by simply remove the "#ifdef CONFIG_KASAN_INLINE"?
>
> Yes, it should just work if you remove the ifdefs in mm/kasan/report.c
> and in include/linux/kasan.h.
>
> Jann, do you have any objections to enabling kasan_non_canonical_hook
> for the outline mode too?

No objections from me.