ntp: Fixup adjtimex freq validation on 32-bit systems

[firefly-linux-kernel-4.4.55.git] / kernel / time / ntp.c

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 28db9bedc857103bc9b35c69602a82598e8828b0..6211d5d6d4656f8d4b25ddfa916980eb63d8e131 100644 (file)
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -631,10 +631,14 @@ int ntp_validate_timex(struct timex *txc)
        if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME)))
                return -EPERM;
 
-       if (txc->modes & ADJ_FREQUENCY) {
-               if (LONG_MIN / PPM_SCALE > txc->freq)
+       /*
+        * Check for potential multiplication overflows that can
+        * only happen on 64-bit systems:
+        */
+       if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) {
+               if (LLONG_MIN / PPM_SCALE > txc->freq)
                        return -EINVAL;
-               if (LONG_MAX / PPM_SCALE < txc->freq)
+               if (LLONG_MAX / PPM_SCALE < txc->freq)
                        return -EINVAL;
        }