ntp: Fixup adjtimex freq validation on 32-bit systems

[pandora-kernel.git] / kernel / time / ntp.c

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index f1eb182..34fd01e 100644 (file)
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -608,6 +608,17 @@ int do_adjtimex(struct timex *txc)
                        return -EINVAL;
        }
 
+       /*
+        * 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 (LLONG_MAX / PPM_SCALE < txc->freq)
+                       return -EINVAL;
+       }
+
        if (txc->modes & ADJ_SETOFFSET) {
                struct timespec delta;
                delta.tv_sec  = txc->time.tv_sec;