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From:   Inigo Huguet <ihuguet@redhat.com>
Date:   Wed, 5 May 2021 13:23:46 +0200
Message-ID: <CACT4oudp9Je55zjg7N8QFDWi5h3kmzMj6syfdi3KgAqQOVgPMA@mail.gmail.com>
Subject: Re: rtlwifi: potential bugs
To:     pkshih@realtek.com, linux-wireless@vger.kernel.org
Cc:     Ivan Vecera <ivecera@redhat.com>
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On Fri, Apr 23, 2021 at 2:56 PM Inigo Huguet <ihuguet@redhat.com> wrote:
>
> Hello,
>
> Executing some static analysis on the kernel, we've got this results
> affecting rtlwifi drivers:
>
> Error: IDENTICAL_BRANCHES (CWE-398): [#def212]
> kernel-5.11.0-0.rc7.151/linux-5.11.0-0.rc7.151.el9.x86_64/drivers/net/wir=
eless/realtek/rtlwifi/btcoexist/halbtc8821a2ant.c:2813:
> identical_branches: The same code is executed regardless of whether
> "bt_rssi_state =3D=3D BTC_RSSI_STATE_HIGH || bt_rssi_state =3D=3D
> BTC_RSSI_STATE_STAY_HIGH" is true, because the 'then' and 'else'
> branches are identical. Should one of the branches be modified, or the
> entire 'if' statement replaced?
> # 2811|   }
> # 2812|
> # 2813|-> if ((bt_rssi_state =3D=3D BTC_RSSI_STATE_HIGH) ||
> # 2814|      (bt_rssi_state =3D=3D BTC_RSSI_STATE_STAY_HIGH)) {
> # 2815|   btc8821a2ant_ps_tdma(btcoexist, NORMAL_EXEC, true, 23);
>
> Error: IDENTICAL_BRANCHES (CWE-398): [#def213]
> kernel-5.11.0-0.rc7.151/linux-5.11.0-0.rc7.151.el9.x86_64/drivers/net/wir=
eless/realtek/rtlwifi/btcoexist/halbtc8821a2ant.c:2947:
> identical_branches: The same code is executed regardless of whether
> "bt_rssi_state =3D=3D BTC_RSSI_STATE_HIGH || bt_rssi_state =3D=3D
> BTC_RSSI_STATE_STAY_HIGH" is true, because the 'then' and 'else'
> branches are identical. Should one of the branches be modified, or the
> entire 'if' statement replaced?
> # 2945|   }
> # 2946|
> # 2947|-> if ((bt_rssi_state =3D=3D BTC_RSSI_STATE_HIGH) ||
> # 2948|      (bt_rssi_state =3D=3D BTC_RSSI_STATE_STAY_HIGH))
> # 2949|   btc8821a2ant_ps_tdma(btcoexist, NORMAL_EXEC, true, 26);
>
> Error: IDENTICAL_BRANCHES (CWE-398): [#def214]
> kernel-5.11.0-0.rc7.151/linux-5.11.0-0.rc7.151.el9.x86_64/drivers/net/wir=
eless/realtek/rtlwifi/btcoexist/halbtc8821a2ant.c:3135:
> identical_branches: The same code is executed regardless of whether
> "wifi_bw =3D=3D BTC_WIFI_BW_LEGACY" is true, because the 'then' and 'else=
'
> branches are identical. Should one of the branches be modified, or the
> entire 'if' statement replaced?
> # 3133|   btcoexist->btc_get(btcoexist, BTC_GET_U4_WIFI_BW, &wifi_bw);
> # 3134|
> # 3135|-> if (wifi_bw =3D=3D BTC_WIFI_BW_LEGACY) {
> # 3136|   /* for HID at 11b/g mode */
> # 3137|   btc8821a2ant_coex_table(btcoexist, NORMAL_EXEC, 0x55ff55ff,
>
> Error: IDENTICAL_BRANCHES (CWE-398): [#def215]
> kernel-5.11.0-0.rc7.151/linux-5.11.0-0.rc7.151.el9.x86_64/drivers/net/wir=
eless/realtek/rtlwifi/btcoexist/halbtc8821a2ant.c:3324:
> identical_branches: The same code is executed regardless of whether
> "bt_rssi_state =3D=3D BTC_RSSI_STATE_HIGH || bt_rssi_state =3D=3D
> BTC_RSSI_STATE_STAY_HIGH" is true, because the 'then' and 'else'
> branches are identical. Should one of the branches be modified, or the
> entire 'if' statement replaced?
> # 3322|   }
> # 3323|
> # 3324|-> if ((bt_rssi_state =3D=3D BTC_RSSI_STATE_HIGH) ||
> # 3325|      (bt_rssi_state =3D=3D BTC_RSSI_STATE_STAY_HIGH)) {
> # 3326|   btc8821a2ant_ps_tdma(btcoexist, NORMAL_EXEC, true, 23);
>
>
> In my opinion, they seem to be real bugs. However, it's very difficult
> to imagine what actions must be taken on each branch of the if-else
> because they strongly depend on magic numbers, which are different
> configurations for the hw, I guess.
>
> Can the maintainers confirm if these are real bugs and see how to fix the=
m?
>
> Regards
> --
> =C3=8D=C3=B1igo Huguet

Hello,

A few weeks ago I sent the message above notifying a potential bug in
rtlwifi module. I just wanted to be sure that it has been received.
Can the maintainers acknowledge whether they have seen it?

Thanks!
--=20
=C3=8D=C3=B1igo Huguet