ptp: validate the requested frequency adjustment.

[cascardo/linux.git] / drivers / ptp / ptp_clock.c

diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index e25d2bc..296b0ec 100644 (file)
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -142,7 +142,10 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
                delta = ktime_to_ns(kt);
                err = ops->adjtime(ops, delta);
        } else if (tx->modes & ADJ_FREQUENCY) {
-               err = ops->adjfreq(ops, scaled_ppm_to_ppb(tx->freq));
+               s32 ppb = scaled_ppm_to_ppb(tx->freq);
+               if (ppb > ops->max_adj || ppb < -ops->max_adj)
+                       return -ERANGE;
+               err = ops->adjfreq(ops, ppb);
                ptp->dialed_frequency = tx->freq;
        } else if (tx->modes == 0) {
                tx->freq = ptp->dialed_frequency;