From 9f7abdd500269d044388593654a85afc3e174b91 Mon Sep 17 00:00:00 2001 From: Li Hua Date: Wed, 16 Nov 2022 10:07:06 +0800 Subject: watchdog: pcwd_usb: Fix attempting to access uninitialized memory MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 7d06c07c67100fd0f8e6b3ab7145ce789f788117 ] The stack variable msb and lsb may be used uninitialized in function usb_pcwd_get_temperature and usb_pcwd_get_timeleft when usb card no response. The build waring is: drivers/watchdog/pcwd_usb.c:336:22: error: ‘lsb’ is used uninitialized in this function [-Werror=uninitialized] *temperature = (lsb * 9 / 5) + 32; ~~~~^~~ drivers/watchdog/pcwd_usb.c:328:21: note: ‘lsb’ was declared here unsigned char msb, lsb; ^~~ cc1: all warnings being treated as errors scripts/Makefile.build:250: recipe for target 'drivers/watchdog/pcwd_usb.o' failed make[3]: *** [drivers/watchdog/pcwd_usb.o] Error 1 Fixes: b7e04f8c61a4 ("mv watchdog tree under drivers") Signed-off-by: Li Hua Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20221116020706.70847-1-hucool.lihua@huawei.com Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin --- drivers/watchdog/pcwd_usb.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/watchdog/pcwd_usb.c b/drivers/watchdog/pcwd_usb.c index 1bdaf17c1d38..8202f0a6b093 100644 --- a/drivers/watchdog/pcwd_usb.c +++ b/drivers/watchdog/pcwd_usb.c @@ -325,7 +325,8 @@ static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t) static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature) { - unsigned char msb, lsb; + unsigned char msb = 0x00; + unsigned char lsb = 0x00; usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb); @@ -341,7 +342,8 @@ static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd, int *time_left) { - unsigned char msb, lsb; + unsigned char msb = 0x00; + unsigned char lsb = 0x00; /* Read the time that's left before rebooting */ /* Note: if the board is not yet armed then we will read 0xFFFF */ -- cgit v1.2.3