drivers/s390/char/keyboard.c NULL pointer reference

From: sohu0106
Date: Thu Aug 03 2017 - 09:58:00 EST

Local users able to send the NULL arg argument to kbd_ioctl(), which could cause kernel crash

diff --git a/keyboard.cÂ
index ba0e4f9..3ec16b1 100644
--- a/keyboard.c
+++ b/keyboard.c
@@ -456,6 +456,8 @@ int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
    int perm;
    argp = (void __user *)arg;
+ Â Â Â if( !argp )
+ Â Â Â Â Â Â Â return -EFAULT;
    Â* To have permissions to do most of the vt ioctls, we either have