ptp: oops in ptp_ioctl()

If we pass ERR_PTR(-EFAULT) to kfree() then it's going to oops.

Fixes: 2ece068e1b1d ('ptp: use memdup_user().')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 0b1ac6be69ce..d637c933c8a9 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -211,6 +211,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
                 sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
                 if (IS_ERR(sysoff)) {
                         err = PTR_ERR(sysoff);
+                        sysoff = NULL;
                         break;
                 }
                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {