Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 4 Feb 2021 14:22:10 -0600
From:   Josh Poimboeuf <jpoimboe@redhat.com>
To:     Ivan Babrou <ivan@cloudflare.com>
Cc:     kernel-team <kernel-team@cloudflare.com>,
        Ignat Korchagin <ignat@cloudflare.com>,
        Hailong liu <liu.hailong6@zte.com.cn>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
        Miroslav Benes <mbenes@suse.cz>,
        Julien Thierry <jthierry@redhat.com>,
        Jiri Slaby <jirislaby@kernel.org>, kasan-dev@googlegroups.com,
        linux-mm@kvack.org, linux-kernel <linux-kernel@vger.kernel.org>,
        Alasdair Kergon <agk@redhat.com>,
        Mike Snitzer <snitzer@redhat.com>, dm-devel@redhat.com,
        "Steven Rostedt (VMware)" <rostedt@goodmis.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        Andrii Nakryiko <andriin@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@chromium.org>,
        Robert Richter <rric@kernel.org>,
        "Joel Fernandes (Google)" <joel@joelfernandes.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        bpf@vger.kernel.org, Alexey Kardashevskiy <aik@ozlabs.ru>
Subject: Re: BUG: KASAN: stack-out-of-bounds in
 unwind_next_frame+0x1df5/0x2650
Message-ID: <20210204202210.4awpfn2ckdv7h5cf@treble>
References: <CABWYdi3HjduhY-nQXzy2ezGbiMB1Vk9cnhW2pMypUa+P1OjtzQ@mail.gmail.com>
 <CABWYdi27baYc3ShHcZExmmXVmxOQXo9sGO+iFhfZLq78k8iaAg@mail.gmail.com>
 <YBrTaVVfWu2R0Hgw@hirez.programming.kicks-ass.net>
 <CABWYdi2ephz57BA8bns3reMGjvs5m0hYp82+jBLZ6KD3Ba6zdQ@mail.gmail.com>
 <20210203190518.nlwghesq75enas6n@treble>
 <CABWYdi1ya41Ju9SsHMtRQaFQ=s8N23D3ADn6OV6iBwWM6H8=Zw@mail.gmail.com>
 <20210203232735.nw73kugja56jp4ls@treble>
 <CABWYdi1zd51Jb35taWeGC-dR9SChq-4ixvyKms3KOKgV0idfPg@mail.gmail.com>
 <20210204001700.ry6dpqvavcswyvy7@treble>
 <CABWYdi2GsFW9ExXAQ55tvr+K86eY15T1XFoZDDBro9hJK5Gpqg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <CABWYdi2GsFW9ExXAQ55tvr+K86eY15T1XFoZDDBro9hJK5Gpqg@mail.gmail.com>
Precedence: bulk

On Thu, Feb 04, 2021 at 11:51:44AM -0800, Ivan Babrou wrote:
> >  .macro FUNC_SAVE
> >          #the number of pushes must equal STACK_OFFSET
> > +       push    %rbp
> > +       mov     %rsp, %rbp
> >          push    %r12
> >          push    %r13
> >          push    %r14
> > @@ -271,12 +273,14 @@ VARIABLE_OFFSET = 16*8
> >  .endm
> >
> >  .macro FUNC_RESTORE
> > +        add     $VARIABLE_OFFSET, %rsp
> >          mov     %r14, %rsp
> >
> >          pop     %r15
> >          pop     %r14
> >          pop     %r13
> >          pop     %r12
> > +       pop     %rbp
> >  .endm
> >
> >  # Encryption of a single block
> >
> 
> This patch seems to fix the following warning:
> 
> [  147.995699][    C0] WARNING: stack going in the wrong direction? at
> glue_xts_req_128bit+0x21f/0x6f0 [glue_helper]
> 
> Or at least I cannot see it anymore when combined with your other
> patch, not sure if it did the trick by itself.
> 
> This sounds like a good reason to send them both.

Ok, that's what I expected.

The other patch fixed the unwinder failure mode to be the above
(harmless) unwinder warning, instead of a disruptive KASAN failure.

This patch fixes the specific underlying crypto unwinding metadata
issue.

I'll definitely be sending both fixes.  The improved failure mode patch
will come first because it's more urgent and lower risk.

-- 
Josh