target/linux/generic/patches-3.9/993-mpcore_wdt_fix_wdioc_setoptions_handling.patch

   1 According to the include/linux/watchdog.h WDIOC_SETOPTIONS is
   2 classified as 'read from device' ioctl call:
   3   #define WDIOC_SETOPTIONS        _IOR(WATCHDOG_IOCTL_BASE, 4, int)
   4
   5 However, the driver 'mpcore_wdt' performs 'copy_from_user' only if
   6 _IOC_WRITE is set, thus the local variable 'uarg' which is used in
   7 WDIOC_SETOPTIONS handling remains uninitialized.
   8
   9 The proper way to fix this is to bind WDIOC_SETOPTIONS to _IOW,
  10 but this will break compatibility.
  11 So adding additional condition for performing 'copy_from_user'.
  12
  13 Signed-off-by: Vitaly Kuzmichev <vkuzmichev@mvista.com>
  14 ---
  15  drivers/watchdog/mpcore_wdt.c |    3 ++-
  16  1 files changed, 2 insertions(+), 1 deletions(-)
  17
  18 --- a/drivers/watchdog/mpcore_wdt.c
  19 +++ b/drivers/watchdog/mpcore_wdt.c
  20 @@ -235,7 +235,8 @@ static long mpcore_wdt_ioctl(struct file
  21         if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
  22                 return -ENOTTY;
  23
  24 -       if (_IOC_DIR(cmd) & _IOC_WRITE) {
  25 +       if ((_IOC_DIR(cmd) & _IOC_WRITE)
  26 +                       || cmd == WDIOC_SETOPTIONS) {
  27                 ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
  28                 if (ret)
  29                         return -EFAULT;