Re: WARNING in perf_group_attach

[Song Liu]

> On Nov 22, 2019, at 8:29 AM, syzbot <syzbot+23fe48cbe532abffa52e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> 
> syzbot has bisected this bug to:
> 
> commit 33ea4b24277b06dbc55d7f5772a46f029600255e
> Author: Song Liu <songliubraving@xxxxxx>
> Date:   Wed Dec 6 22:45:16 2017 +0000
> 
>    perf/core: Implement the 'perf_uprobe' PMU
> 
> bisection log:  https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1038fecae00000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=twva4o7mjqFOvS4tIPaO-5jjo-XAwT9qjmMqY7gRsLM&s=3ABayY9CyfQkmQs0KgB2fcFws0p7utMNa7tcrLE0b4Y&e=start commit:   0072a0c1 Merge tag 'media/v4.20-4' of git://git.kernel.org..
> git tree:       upstream
> final crash:    https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1238fecae00000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=twva4o7mjqFOvS4tIPaO-5jjo-XAwT9qjmMqY7gRsLM&s=CZ1NX6DT4kikiKc9qfHrpHrBGrPBNOzUUwcp-avrDlo&e=console output: https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1438fecae00000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=twva4o7mjqFOvS4tIPaO-5jjo-XAwT9qjmMqY7gRsLM&s=Gbwfq2mU_2xkXjM2LVOht4iV94BqNlAVlldmf99YE2o&e=kernel config:  https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3Db9cc5a440391cbfd&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=twva4o7mjqFOvS4tIPaO-5jjo-XAwT9qjmMqY7gRsLM&s=80FYgyg5lxOA80Ae-t5h5madX7fI4JOulTaVL6A5OIE&e=dashboard link: https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D23fe48cbe532abffa52e&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=twva4o7mjqFOvS4tIPaO-5jjo-XAwT9qjmMqY7gRsLM&s=CLG4xu3n98RYL4iBP5vb_BVLur-IxZkzQf5KMgJKEBQ&e=syz repro:      https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D135e93eb400000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=twva4o7mjqFOvS4tIPaO-5jjo-XAwT9qjmMqY7gRsLM&s=rE9GDnbBf2V3RMoW8TmNFJxPVfG2W27IzFAQ4534Yok&e=C reproducer:   https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D13189415400000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=twva4o7mjqFOvS4tIPaO-5jjo-XAwT9qjmMqY7gRsLM&s=zu43yb0MPn0VZeQKwG-EDUHqYYgHgJhJrRcYp6dl-dE&e=
> Reported-by: syzbot+23fe48cbe532abffa52e@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
> 
> For information about bisection process see: https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ-23bisection&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=i6WobKxbeG3slzHSIOxTVtYIJw7qjCE6S0spDTKL-J4&m=twva4o7mjqFOvS4tIPaO-5jjo-XAwT9qjmMqY7gRsLM&s=YWXIJgdau0PZoF8t4mWq-2xQY88lKIzCF0JnR-ZM4Ao&e=


Thanks for the report. I will look into the fix. 

Song