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References: <CAB_54W50xKFCWZ5vYuDG2p4ijpd63cSutRrV4MLs9oasLmKgzQ@mail.gmail.com>
 <20220103120925.25207-1-paskripkin@gmail.com>
In-Reply-To: <20220103120925.25207-1-paskripkin@gmail.com>
From:   Alexander Aring <alex.aring@gmail.com>
Date:   Mon, 3 Jan 2022 10:27:12 -0500
Message-ID: <CAB_54W7jpTJ-PicyZLTvY4+ELdQVgELR1wRPrSjbZOBLzz46Jg@mail.gmail.com>
Subject: Re: [PATCH v2] ieee802154: atusb: fix uninit value in atusb_set_extended_addr
To:     Pavel Skripkin <paskripkin@gmail.com>
Cc:     Stefan Schmidt <stefan@datenfreihafen.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        linux-wpan - ML <linux-wpan@vger.kernel.org>,
        "open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
        kernel list <linux-kernel@vger.kernel.org>,
        Alexander Potapenko <glider@google.com>
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Hi,

On Mon, 3 Jan 2022 at 07:09, Pavel Skripkin <paskripkin@gmail.com> wrote:
>
> Alexander reported a use of uninitialized value in
> atusb_set_extended_addr(), that is caused by reading 0 bytes via
> usb_control_msg().
>
> Fix it by validating if the number of bytes transferred is actually
> correct, since usb_control_msg() may read less bytes, than was requested
> by caller.
>
> Fail log:
>
> BUG: KASAN: uninit-cmp in ieee802154_is_valid_extended_unicast_addr include/linux/ieee802154.h:310 [inline]
> BUG: KASAN: uninit-cmp in atusb_set_extended_addr drivers/net/ieee802154/atusb.c:1000 [inline]
> BUG: KASAN: uninit-cmp in atusb_probe.cold+0x29f/0x14db drivers/net/ieee802154/atusb.c:1056
> Uninit value used in comparison: 311daa649a2003bd stack handle: 000000009a2003bd
>  ieee802154_is_valid_extended_unicast_addr include/linux/ieee802154.h:310 [inline]
>  atusb_set_extended_addr drivers/net/ieee802154/atusb.c:1000 [inline]
>  atusb_probe.cold+0x29f/0x14db drivers/net/ieee802154/atusb.c:1056
>  usb_probe_interface+0x314/0x7f0 drivers/usb/core/driver.c:396
>
> Fixes: 7490b008d123 ("ieee802154: add support for atusb transceiver")
> Reported-by: Alexander Potapenko <glider@google.com>
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>

Acked-by: Alexander Aring <aahringo@redhat.com>

Although I think if such error exists the most common solution would
be to replug the usb device and hope it gets resolved? A retry with a
maximum amount would be another try... However, let's hope those
errors are rare and we care about them when they occur.

Thanks.

- Alex