3 files changed, 44 insertions, 11 deletions

diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index 603bec2913b..06177ba10a1 100644
--- a/include/linux/ktime.h
+++ b/include/linux/ktime.h
@@ -58,13 +58,6 @@ union ktime {
 
 typedef union ktime ktime_t;		/* Kill this */
 
-#define KTIME_MAX			((s64)~((u64)1 << 63))
-#if (BITS_PER_LONG == 64)
-# define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
-#else
-# define KTIME_SEC_MAX			LONG_MAX
-#endif
-
 /*
  * ktime_t definitions when using the 64-bit scalar representation:
  */
diff --git a/include/linux/time.h b/include/linux/time.h
index c81c5e40fcb..b0bbd8f0130 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -107,11 +107,29 @@ static inline struct timespec timespec_sub(struct timespec lhs,
 	return ts_delta;
 }
 
+#define KTIME_MAX			((s64)~((u64)1 << 63))
+#if (BITS_PER_LONG == 64)
+# define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
+#else
+# define KTIME_SEC_MAX			LONG_MAX
+#endif
+
 /*
  * Returns true if the timespec is norm, false if denorm:
  */
-#define timespec_valid(ts) \
-	(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
+static inline bool timespec_valid(const struct timespec *ts)
+{
+	/* Dates before 1970 are bogus */
+	if (ts->tv_sec < 0)
+		return false;
+	/* Can't have more nanoseconds then a second */
+	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
+		return false;
+	/* Disallow values that could overflow ktime_t */
+	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
+		return false;
+	return true;
+}
 
 extern void read_persistent_clock(struct timespec *ts);
 extern void read_boot_clock(struct timespec *ts);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e16af197a2b..898bef066a4 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -427,7 +427,7 @@ int do_settimeofday(const struct timespec *tv)
 	struct timespec ts_delta, xt;
 	unsigned long flags;
 
-	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+	if (!timespec_valid(tv))
 		return -EINVAL;
 
 	write_seqlock_irqsave(&tk->lock, flags);
@@ -463,6 +463,8 @@ int timekeeping_inject_offset(struct timespec *ts)
 {
 	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
+	struct timespec tmp;
+	int ret = 0;
 
 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
@@ -471,10 +473,17 @@ int timekeeping_inject_offset(struct timespec *ts)
 
 	timekeeping_forward_now(tk);
 
+	/* Make sure the proposed value is valid */
+	tmp = timespec_add(tk_xtime(tk),  *ts);
+	if (!timespec_valid(&tmp)) {
+		ret = -EINVAL;
+		goto error;
+	}
 
 	tk_xtime_add(tk, ts);
 	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
 
+error: /* even if we error out, we forwarded the time, so call update */
 	timekeeping_update(tk, true);
 
 	write_sequnlock_irqrestore(&tk->lock, flags);
@@ -482,7 +491,7 @@ int timekeeping_inject_offset(struct timespec *ts)
 	/* signal hrtimers about time change */
 	clock_was_set();
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL(timekeeping_inject_offset);
 
@@ -649,7 +658,20 @@ void __init timekeeping_init(void)
 	struct timespec now, boot, tmp;
 
 	read_persistent_clock(&now);
+	if (!timespec_valid(&now)) {
+		pr_warn("WARNING: Persistent clock returned invalid value!\n"
+			"         Check your CMOS/BIOS settings.\n");
+		now.tv_sec = 0;
+		now.tv_nsec = 0;
+	}
+
 	read_boot_clock(&boot);
+	if (!timespec_valid(&boot)) {
+		pr_warn("WARNING: Boot clock returned invalid value!\n"
+			"         Check your CMOS/BIOS settings.\n");
+		boot.tv_sec = 0;
+		boot.tv_nsec = 0;
+	}
 
 	seqlock_init(&tk->lock);