Merge branch 'fortglx/3.19-stable/time' of https://git.linaro.org/people/john.stultz/linux into timers/urgent

Pull urgent fixes from John Stultz:

  Two urgent fixes for user triggerable time related overflow issues
diff --git a/include/linux/time.h b/include/linux/time.h
index 203c2ad..beebe3a 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -110,6 +110,19 @@
 	return true;
 }
 
+static inline bool timeval_valid(const struct timeval *tv)
+{
+	/* Dates before 1970 are bogus */
+	if (tv->tv_sec < 0)
+		return false;
+
+	/* Can't have more microseconds then a second */
+	if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
+		return false;
+
+	return true;
+}
+
 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 
 #define CURRENT_TIME		(current_kernel_time())
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 87a346f..28bf91c 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -633,6 +633,13 @@
 	if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME)))
 		return -EPERM;
 
+	if (txc->modes & ADJ_FREQUENCY) {
+		if (LONG_MIN / PPM_SCALE > txc->freq)
+			return -EINVAL;
+		if (LONG_MAX / PPM_SCALE < txc->freq)
+			return -EINVAL;
+	}
+
 	return 0;
 }
 
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 65015ff..887e7d5 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -196,6 +196,10 @@
 	if (tv) {
 		if (copy_from_user(&user_tv, tv, sizeof(*tv)))
 			return -EFAULT;
+
+		if (!timeval_valid(&user_tv))
+			return -EINVAL;
+
 		new_ts.tv_sec = user_tv.tv_sec;
 		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
 	}