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From:   Alexander Potapenko <glider@google.com>
Date:   Mon, 28 Oct 2019 14:17:48 +0100
Message-ID: <CAG_fn=VLxj9xKd_Wxm0cA1Lo7E6YG4SBsZ9EFnFj94TbE-6aPg@mail.gmail.com>
Subject: Re: KMSAN: uninit-value in get_term_name
To:     Takashi Iwai <tiwai@suse.de>
Cc:     syzbot <syzbot+8f2612936028bfd28f28@syzkaller.appspotmail.com>,
        allison@lohutok.net, alsa-devel@alsa-project.org,
        benquike@gmail.com, dan.carpenter@oracle.com,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        LKML <linux-kernel@vger.kernel.org>, perex@perex.cz,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Takashi Iwai <tiwai@suse.com>, wang6495@umn.edu,
        yuehaibing@huawei.com
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On Mon, Oct 28, 2019 at 2:13 PM Takashi Iwai <tiwai@suse.de> wrote:
>
> On Mon, 28 Oct 2019 11:32:07 +0100,
> syzbot wrote:
> >
> > Uninit was stored to memory at:
> >  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline]
> >  kmsan_internal_chain_origin+0xbd/0x180 mm/kmsan/kmsan.c:319
> >  __msan_chain_origin+0x6b/0xd0 mm/kmsan/kmsan_instr.c:179
> >  parse_term_proc_unit+0x73d/0x7e0 sound/usb/mixer.c:896
> >  __check_input_term+0x13ef/0x2360 sound/usb/mixer.c:989
>
> So this comes from the invalid descriptor for a processing unit, and
> it's very likely the same issue as already spotted -- the validator up
> to 5.3-rc4 had a bug that passed the invalid descriptor falsely.
> This should have been covered by 5.3-rc5, commit ba8bf0967a15 ("ALSA:
> usb-audio: Fix copy&paste error in the validator").
Ah, thanks. Looks like I need to rebase the KMSAN tree.
>
> thanks,
>
> Takashi


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Alexander Potapenko
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