According to the include/linux/watchdog.h WDIOC_SETOPTIONS is
classified as 'read from device' ioctl call:
#define WDIOC_SETOPTIONS _IOR(WATCHDOG_IOCTL_BASE, 4, int)
However, the driver 'mpcore_wdt' performs 'copy_from_user' only if
_IOC_WRITE is set, thus the local variable 'uarg' which is used in
WDIOC_SETOPTIONS handling remains uninitialized.
The proper way to fix this is to bind WDIOC_SETOPTIONS to _IOW,
but this will break compatibility.
So adding additional condition for performing 'copy_from_user'.
Signed-off-by: Vitaly Kuzmichev <vkuzmichev@xxxxxxxxxx>
---
drivers/watchdog/mpcore_wdt.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c
index efde50b..f99e49e 100644
--- a/drivers/watchdog/mpcore_wdt.c
+++ b/drivers/watchdog/mpcore_wdt.c
@@ -233,7 +233,8 @@ static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
return -ENOTTY;
- if (_IOC_DIR(cmd) & _IOC_WRITE) {
+ if ((_IOC_DIR(cmd) & _IOC_WRITE)
+ || cmd == WDIOC_SETOPTIONS) {
ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
if (ret)
return -EFAULT;
--
1.7.3.4
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