fix uninitialized struct data leak

This change clears the tm structure on the stack before filling it in. This guarantees that the whole structure is initialized, and as such, no uninitialized stack data is copied to the caller.

minix/drivers/clock/readclock/readclock.c

@@ -7,6 +7,7 @@
 #include <time.h>
 #include <errno.h>
 #include <lib.h>
+#include <string.h>
 #include <minix/type.h>
 #include <minix/const.h>
 #include <minix/callnr.h>
@@ -70,6 +71,7 @@ main(int argc, char **argv)
 		switch (m.m_type) {
 		case RTCDEV_GET_TIME:
 			/* Any user can read the time */
+			memset(&t, 0x00, sizeof(t));
 			reply_status = rtc.get_time(&t, m.m_lc_readclock_rtcdev.flags);
 			if (reply_status != OK) {
 				break;