[PATCH] wifi: rtl818x: initialize eeprom_93cx6 struct to zero

[PATCH] wifi: rtl818x: initialize eeprom_93cx6 struct to zero

[stf_xl]

From: Stanislaw Gruszka <stf_xl@wp.pl>

Commit 7738a7ab9d12 ("misc: eeprom: eeprom_93cx6: Add quirk for extra
read clock cycle") added extra 'quirk' field to struct eeprom_93cx6.

Many existing users of eeprom_93cx6, including rtl818x drivers, allocate
the structure on the stack without initializing all fields. As a result,
the added quirk field has an undefined value and can randomly cause
reading wrong data from the EEPROM.

Fix by initializing the structures with {}.

Fixes: 7738a7ab9d12 ("misc: eeprom: eeprom_93cx6: Add quirk for extra read clock cycle")
Cc: stable@kernel.org # v6.13+
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
---
 drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c | 2 +-
 drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
index 070c0431c482..4a5989172a5e 100644
--- a/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
+++ b/drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c
@@ -1652,7 +1652,7 @@ static void rtl8180_eeprom_register_write(struct eeprom_93cx6 *eeprom)
 
 static void rtl8180_eeprom_read(struct rtl8180_priv *priv)
 {
-	struct eeprom_93cx6 eeprom;
+	struct eeprom_93cx6 eeprom = {};
 	int eeprom_cck_table_adr;
 	u16 eeprom_val;
 	int i;
diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
index 1d21c468a236..a766712187f7 100644
--- a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
+++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
@@ -1445,7 +1445,7 @@ static int rtl8187_probe(struct usb_interface *intf,
 	struct usb_device *udev = interface_to_usbdev(intf);
 	struct ieee80211_hw *dev;
 	struct rtl8187_priv *priv;
-	struct eeprom_93cx6 eeprom;
+	struct eeprom_93cx6 eeprom = {};
 	struct ieee80211_channel *channel;
 	const char *chip_name;
 	u16 txpwr, reg;
-- 
2.50.1

RE: [PATCH] wifi: rtl818x: initialize eeprom_93cx6 struct to zero

[Ping-Ke Shih]

stf_xl@wp.pl <stf_xl@wp.pl> wrote:
> From: Stanislaw Gruszka <stf_xl@wp.pl>
> 
> Commit 7738a7ab9d12 ("misc: eeprom: eeprom_93cx6: Add quirk for extra
> read clock cycle") added extra 'quirk' field to struct eeprom_93cx6.
> 
> Many existing users of eeprom_93cx6, including rtl818x drivers, allocate
> the structure on the stack without initializing all fields. As a result,
> the added quirk field has an undefined value and can randomly cause
> reading wrong data from the EEPROM.
> 
> Fix by initializing the structures with {}.
> 
> Fixes: 7738a7ab9d12 ("misc: eeprom: eeprom_93cx6: Add quirk for extra read clock cycle")
> Cc: stable@kernel.org # v6.13+
> Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>

Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>