time: Verify time values in adjtimex ADJ_SETOFFSET to avoid overflow

[cascardo/linux.git] / include / linux / time.h

diff --git a/include/linux/time.h b/include/linux/time.h
index beebe3a..297f09f 100644 (file)
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -125,6 +125,32 @@ static inline bool timeval_valid(const struct timeval *tv)
 
 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 
+/*
+ * Validates if a timespec/timeval used to inject a time offset is valid.
+ * Offsets can be postive or negative. The value of the timeval/timespec
+ * is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must
+ * always be non-negative.
+ */
+static inline bool timeval_inject_offset_valid(const struct timeval *tv)
+{
+       /* We don't check the tv_sec as it can be positive or negative */
+
+       /* Can't have more microseconds then a second */
+       if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
+               return false;
+       return true;
+}
+
+static inline bool timespec_inject_offset_valid(const struct timespec *ts)
+{
+       /* We don't check the tv_sec as it can be positive or negative */
+
+       /* Can't have more nanoseconds then a second */
+       if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
+               return false;
+       return true;
+}
+
 #define CURRENT_TIME           (current_kernel_time())
 #define CURRENT_TIME_SEC       ((struct timespec) { get_seconds(), 0 })