drivers/char/hpet.c: fix information leak to userland

Structure info is copied to userland with some padding fields unitialized.
It leads to leaking of stack memory.

[akpm@linux-foundation.org: remove now-unneeded zeroing of info->hi_ireqfreq]
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/hpet.c

@@ -596,11 +596,10 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
 		break;
 	case HPET_INFO:
 		{
+			memset(info, 0, sizeof(*info));
 			if (devp->hd_ireqfreq)
 				info->hi_ireqfreq =
 					hpet_time_div(hpetp, devp->hd_ireqfreq);
-			else
-				info->hi_ireqfreq = 0;
 			info->hi_flags =
 			    readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
 			info->hi_hpet = hpetp->hp_which;