Re: Re: [PATCH] usb: asix: Fix uninit-value in asix_mdio_write

From: Phong Tran
Date: Sun Nov 10 2019 - 09:11:18 EST




On 11/8/19 6:21 AM, David Miller wrote:
From: Phong Tran <tranmanphong@xxxxxxxxx>
Date: Thu, 7 Nov 2019 07:44:04 +0700

The local variables use without initilization value.
This fixes the syzbot report.

Reported-by: syzbot+7dc7c28d4577bbe55b10@xxxxxxxxxxxxxxxxxxxxxxxxx

Test result:

https://groups.google.com/d/msg/syzkaller-bugs/3H_n05x_sPU/sUoHhxgAAgAJ

Signed-off-by: Phong Tran <tranmanphong@xxxxxxxxx>

There are several more situations in this file where the data blob passed
to asix_read_cmd() is read without pre-initialization not checking the
return value from asix_read_cmd().

So, syzbot can see some of them but not all of them, yet all of them
are buggy and should be fixed.

These kinds of patches drive me absolutely crazy :-)

Really, one of two things needs to happen, either asix_read_cmd() clears
the incoming buffer unconditionally,

thank you for your suggestion.
Sent Patch v2 reply-to this mail thread.

regards,
Phong.