Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 11 Mar 2020 19:09:41 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Holger =?iso-8859-1?Q?Hoffst=E4tte?= 
        <holger@applied-asynchrony.com>
Cc:     linux-kernel@vger.kernel.org, linux@roeck-us.net, shuah@kernel.org,
        stable@vger.kernel.org, Paolo Valente <paolo.valente@linaro.org>
Subject: Re: [PATCH 5.4 000/168] 5.4.25-stable review
Message-ID: <20200311180941.GA3970258@kroah.com>
References: <20200310123635.322799692@linuxfoundation.org>
 <d97347d3-4eea-f5e1-8a3c-a12410e9ad5f@applied-asynchrony.com>
 <20200310143527.GB3376131@kroah.com>
 <daf30758-fe28-0709-7908-91bb99ee5e39@applied-asynchrony.com>
 <20200310150018.GA3422873@kroah.com>
 <1371d06f-306b-7e42-3871-fb1a0d7936bf@applied-asynchrony.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1371d06f-306b-7e42-3871-fb1a0d7936bf@applied-asynchrony.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, Mar 10, 2020 at 04:07:23PM +0100, Holger Hoffst?tte wrote:
> On 3/10/20 4:00 PM, Greg Kroah-Hartman wrote:
> > On Tue, Mar 10, 2020 at 03:51:01PM +0100, Holger Hoffst?tte wrote:
> > > On 3/10/20 3:35 PM, Greg Kroah-Hartman wrote:
> > > > On Tue, Mar 10, 2020 at 03:02:37PM +0100, Holger Hoffst?tte wrote:
> > > > > On 3/10/20 1:37 PM, Greg Kroah-Hartman wrote:
> > > > > > This is the start of the stable review cycle for the 5.4.25 release.
> > > > > 
> > > > > This fails to compile due to broken patch 001/168:
> > > > > "block, bfq: get a ref to a group when adding it to a service tree":
> > > > > 
> > > > > ..
> > > > > block/bfq-wf2q.c: In function 'bfq_get_entity':
> > > > > ./include/linux/kernel.h:994:51: error: 'struct bfq_group' has no member named 'entity'
> > > > > ..
> > > > > 
> > > > > The calls to bfq_get_entity::bfqg_and_blkg_get and bfq_forget_entity::bfqg_and_blkg_put
> > > > > in bfq-wf2q.c need to be wrapped in #ifdef CONFIG_BFQ_GROUP_IOSCHED, otherwise
> > > > > the build will fail when CONFIG_BFQ_GROUP_IOSCHED is not enabled.
> > > > > This horribly error-prone #ifdef mess was finally removed in upstream commit
> > > > > 4d8340d0d4d9. For 5.4 we'll either need that as well or add them back.
> > > > 
> > > > Ick, that's a mess.
> > > > 
> > > > I'll go drop that patch now, odd that it passed my build tests...
> > > 
> > > Uh, please no? It fixes a rather nasty UAF when cgroups are in use.
> > > Please just add the other upstream commit as well, I confirmed it applies
> > > cleanly and fixes the problem.
> > 
> > I didn't get that from your email at all, sorry.
> > 
> > So, what commits, and in what order, should be applied to 5.4.y at the
> > moment to resolve this issue?
> 
> Just add upstream 4d8340d0d4d9 and it should work. Order shouldn't matter
> (built for me either way) unless you want to follow upstream, in which case
> it should come before "get a ref to a group..". Easy :)

Ok, I've added both back now, and to the 5.5.y tree as well.  Hopefully
that should resolve these build issues.

thanks,

greg k-h