netdev - [PATCH][next] wifi: rtl8xxxu: Fix reads of uninitialized variables hw_ctrl_s1, sw_ctrl

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Date:   Thu, 20 Oct 2022 14:57:09 +0100
From:   Colin Ian King <colin.i.king@...il.com>
To:     Jes Sorensen <Jes.Sorensen@...il.com>,
        Kalle Valo <kvalo@...nel.org>,
        "David S . Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Bitterblue Smith <rtl8821cerfe2@...il.com>,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org
Cc:     kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH][next] wifi: rtl8xxxu: Fix reads of uninitialized variables hw_ctrl_s1, sw_ctrl_s1

Variables hw_ctrl_s1 and sw_ctrl_s1 are not being initialized and
potentially can contain any garbage value. Currently there is an if
statement that sets one or the other of these variables, followed
by an if statement that checks if any of these variables have been
set to a non-zero value. In the case where they may contain
uninitialized non-zero values, the latter if statement may be
taken as true when it was not expected to.

Fix this by ensuring hw_ctrl_s1 and sw_ctrl_s1 are initialized.

Cleans up clang warning:
drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c:432:7: warning:
variable 'hw_ctrl_s1' is used uninitialized whenever 'if' condition is
false [-Wsometimes-uninitialized]
                if (hw_ctrl) {
                    ^~~~~~~
drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c:440:7: note: uninitialized
use occurs here
                if (hw_ctrl_s1 || sw_ctrl_s1) {
                    ^~~~~~~~~~
drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c:432:3: note: remove the 'if'
if its condition is always true
                if (hw_ctrl) {
                ^~~~~~~~~~~~~

Fixes: c888183b21f3 ("wifi: rtl8xxxu: Support new chip RTL8188FU")
Signed-off-by: Colin Ian King <colin.i.king@...il.com>
---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c
index 99610bb2afd5..0025bb32538d 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c
@@ -412,7 +412,7 @@ static void rtl8188f_spur_calibration(struct rtl8xxxu_priv *priv, u8 channel)
 	};
 
 	const u8 threshold = 0x16;
-	bool do_notch, hw_ctrl, sw_ctrl, hw_ctrl_s1, sw_ctrl_s1;
+	bool do_notch, hw_ctrl, sw_ctrl, hw_ctrl_s1 = 0, sw_ctrl_s1 = 0;
 	u32 val32, initial_gain, reg948;
 
 	val32 = rtl8xxxu_read32(priv, REG_OFDM0_RX_D_SYNC_PATH);
-- 
2.37.3