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From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Wed, 23 Sep 2020 17:20:06 +0200
Message-ID: <CACT4Y+ayTBwBwsnV9Kp-vMQ=hgu9-r9g4qzAfd+HdQXX95PX9g@mail.gmail.com>
Subject: Re: general protection fault in perf_misc_flags
To:     Borislav Petkov <bp@alien8.de>
Cc:     Nick Desaulniers <ndesaulniers@google.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        syzbot <syzbot+ce179bc99e64377c24bc@syzkaller.appspotmail.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Jiri Olsa <jolsa@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Ingo Molnar <mingo@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>
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On Wed, Sep 23, 2020 at 12:34 PM Borislav Petkov <bp@alien8.de> wrote:
>
> On Wed, Sep 23, 2020 at 11:24:48AM +0200, Dmitry Vyukov wrote:
> > 3. Run syzkaller locally with custom patches.
>
> Let's say I wanna build the kernel with clang-10 using your .config and
> run it in a vm locally. What are the steps in order to reproduce the
> same workload syzkaller runs in the guest on the GCE so that I can at
> least try get as close as possible to reproducing locally?

It's a random fuzzing workload. You can get this workload by running
syzkaller locally:
https://github.com/google/syzkaller/blob/master/docs/linux/setup_ubuntu-host_qemu-vm_x86-64-kernel.md

The exact clang compiler syzbot used is available here:
https://github.com/google/syzkaller/blob/master/docs/syzbot.md#crash-does-not-reproduce