Messages in this thread | | | Date | Tue, 24 Sep 2013 14:50:50 +0200 | From | Richard Cochran <> | Subject | Re: [PATCH] ptp: add range check on n_samples |
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On Tue, Sep 24, 2013 at 03:05:57PM +0800, Dong Zhu wrote: > From d4eb97e8d5def76d46167c91059147e2c7d33433 Mon Sep 17 00:00:00 2001 > > When using PTP_SYS_OFFSET ioctl to measure the time offset between the > PHC and system clock, we need to specify the number of measurements, the > valid value of n_samples is between 1 to 25. If n_samples <= 0 or > 25 > it makes no sense, so this patch intends to add a range check.
The field, n_samples, is unsigned, so the check is not needed.
Thanks, Richard
> Signed-off-by: Dong Zhu <bluezhudong@gmail.com> > --- > drivers/ptp/ptp_chardev.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c > index 34a0c60..4e85b23 100644 > --- a/drivers/ptp/ptp_chardev.c > +++ b/drivers/ptp/ptp_chardev.c > @@ -104,7 +104,8 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > err = -EFAULT; > break; > } > - if (sysoff->n_samples > PTP_MAX_SAMPLES) { > + if (sysoff->n_samples <= 0 || > + sysoff->n_samples > PTP_MAX_SAMPLES) { > err = -EINVAL; > break; > } > -- > 1.7.11.7 > > -- > Best Regards, > Dong Zhu
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