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Date:   Mon, 28 Oct 2019 14:13:20 +0100
Message-ID: <s5hr22xau8f.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     syzbot <syzbot+8f2612936028bfd28f28@syzkaller.appspotmail.com>
Cc:     <allison@lohutok.net>, <alsa-devel@alsa-project.org>,
        <benquike@gmail.com>, <dan.carpenter@oracle.com>,
        <glider@google.com>, <gregkh@linuxfoundation.org>,
        <linux-kernel@vger.kernel.org>, <perex@perex.cz>,
        <syzkaller-bugs@googlegroups.com>, <tglx@linutronix.de>,
        <tiwai@suse.com>, <wang6495@umn.edu>, <yuehaibing@huawei.com>
Subject: Re: KMSAN: uninit-value in get_term_name
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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").


thanks,

Takashi