Re: WARNING in snd_pcm_plugin_build_mulaw

[Takashi Iwai <tiwai@suse.de>]

On Tue, 01 Sep 2020 14:16:24 +0200,
Fabio Estevam wrote:
> 
> On Tue, Sep 1, 2020 at 7:08 AM syzbot
> <syzbot+23b22dc2e0b81cbfcc95@syzkaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    15bc20c6 Merge tag 'tty-5.9-rc3' of git://git.kernel.org/p..
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=1268efb1900000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=891ca5711a9f1650
> > dashboard link: https://syzkaller.appspot.com/bug?extid=23b22dc2e0b81cbfcc95
> > compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11a95f41900000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11a452f2900000
> >
> > The issue was bisected to:
> >
> > commit f3ca3f5b0966cfc2737178cca8a7a65b09991898
> > Author: Fabio Estevam <festevam@gmail.com>
> > Date:   Fri Mar 27 15:57:21 2020 +0000
> >
> >     dt-bindings: sound: cs42l51: Remove unneeded I2C unit name
> >
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=15395f41900000
> > final oops:     https://syzkaller.appspot.com/x/report.txt?x=17395f41900000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=13395f41900000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+23b22dc2e0b81cbfcc95@syzkaller.appspotmail.com
> > Fixes: f3ca3f5b0966 ("dt-bindings: sound: cs42l51: Remove unneeded I2C unit name")
> 
> The conclusion that this commit caused the problem is strange, since
> this commit is just a yaml documentation fix.

The bisection result must be bogus.  And the issue here is harmless,
merely a superfluous WARN_ON().  I'll work on it later.


thanks,

Takashi