Messages in this thread Patch in this message | | | Date | Tue, 24 Sep 2013 15:05:57 +0800 | From | Dong Zhu <> | Subject | [PATCH] ptp: add range check on n_samples |
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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.
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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