Re: [PATCH v2] arm: kasan: clear stale stack poison

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: "Boy Wu (吳勃誼)" <Boy.Wu@mediatek.com>,
	"linus.walleij@linaro.org" <linus.walleij@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mediatek@lists.infradead.org"
	<linux-mediatek@lists.infradead.org>,
	"andreyknvl@gmail.com" <andreyknvl@gmail.com>,
	"dvyukov@google.com" <dvyukov@google.com>,
	"kasan-dev@googlegroups.com" <kasan-dev@googlegroups.com>,
	"Iverlin Wang (王苳霖)" <Iverlin.Wang@mediatek.com>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"Light Chen (陳昱光)" <Light.Chen@mediatek.com>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"glider@google.com" <glider@google.com>,
	"matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
	"vincenzo.frascino@arm.com" <vincenzo.frascino@arm.com>,
	"angelogioacchino.delregno@collabora.com"
	<angelogioacchino.delregno@collabora.com>
Subject: Re: [PATCH v2] arm: kasan: clear stale stack poison
Date: Mon, 29 Apr 2024 14:11:57 +0100	[thread overview]
Message-ID: <Zi+cnTPS1rgHtneN@shell.armlinux.org.uk> (raw)
In-Reply-To: <f90f5352-30ed-419f-803b-7885b4298868@gmail.com>

On Mon, Apr 29, 2024 at 02:57:35PM +0200, Andrey Ryabinin wrote:
> On 4/29/24 14:42, Russell King (Oracle) wrote:
> > On Mon, Apr 29, 2024 at 07:51:49AM +0000, Boy Wu (吳勃誼) wrote:
> >> On Sun, 2024-04-28 at 15:45 +0100, Russell King (Oracle) wrote:
> >>>  On Fri, Apr 12, 2024 at 10:37:06AM +0200, Linus Walleij wrote:
> >>>> On Wed, Apr 10, 2024 at 9:31 AM boy.wu <boy.wu@mediatek.com> wrote:
> >>>>
> >>>>> From: Boy Wu <boy.wu@mediatek.com>
> >>>>>
> >>>>> We found below OOB crash:
> >>>>
> >>>> Thanks for digging in!
> >>>>
> >>>> Pleas put this patch into Russell's patch tracker so he can apply
> >>> it:
> >>>> https://www.armlinux.org.uk/developer/patches/
> >>>
> >>> Is this a bug fix? If so, having a Fixes: tag would be nice...
> >>>
> >>
> >> This is a patch for cpuidle flow when KASAN enable, that is in ARM64
> >> but not in ARM, so add to ARM.
> >>
> >> The reference commits did not mention fix any commits.
> >> [1] commit 0d97e6d8024c ("arm64: kasan: clear stale stack poison")
> >> [2] commit d56a9ef84bd0 ("kasan, arm64: unpoison stack only with
> >> CONFIG_KASAN_STACK")
> > 
> > These are not suitable for use as a Fixes: tag because these commits
> > refer to code in another part of the tree that has nothing to do with
> > the BUG() dump that is contained within your commit message.
> > 
> > I ask again... Is this a bug fix?
> > 
> > Is it a regression?
> > 
> > Is it something that used to work that no longer works?
> > 
> > When did it break?
> > 
> > Has it always been broken?
> > 
> > Has it been broken since KASAN was introduced on 32-bit ARM?
> > 
> 
> Yes, this is a bug fix and it has been broken since KASAN was introduced on 32-bit ARM.
> So, I think this should be
> 	Fixes: 5615f69bc209 ("ARM: 9016/2: Initialize the mapping of KASan shadow memory")

Brilliant, thanks! Now merged.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!