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Commit 6ff51a99 authored by Li Hua's avatar Li Hua Committed by Greg Kroah-Hartman
Browse files

watchdog: pcwd_usb: Fix attempting to access uninitialized memory 



[ 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: b7e04f8c ("mv watchdog tree under drivers")
Signed-off-by: default avatarLi Hua <hucool.lihua@huawei.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20221116020706.70847-1-hucool.lihua@huawei.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 8c165560

drivers/watchdog/pcwd_usb.c

+4 −2
Original line number Diff line number Diff line
@@ -329,7 +329,8 @@ 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);
@@ -345,7 +346,8 @@ 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 */