netdev - [PATCH net-next] ptp: only allow phase values lower than 1 period

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200803194921.603151-1-olteanv@gmail.com>
Date:   Mon,  3 Aug 2020 22:49:21 +0300
From:   Vladimir Oltean <olteanv@...il.com>
To:     kuba@...nel.org, davem@...emloft.net, netdev@...r.kernel.org
Cc:     richardcochran@...il.com, jacob.e.keller@...el.com
Subject: [PATCH net-next] ptp: only allow phase values lower than 1 period

The way we define the phase (the difference between the time of the
signal's rising edge, and the closest integer multiple of the period),
it doesn't make sense to have a phase value larger than 1 period.

So deny these settings coming from the user.

Signed-off-by: Vladimir Oltean <olteanv@...il.com>
---
 drivers/ptp/ptp_chardev.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index e0e6f85966e1..02fcd5e8b998 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -218,6 +218,19 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 					break;
 				}
 			}
+			if (perout->flags & PTP_PEROUT_PHASE) {
+				/*
+				 * The phase should be specified modulo the
+				 * period, therefore anything larger than 1
+				 * period is invalid.
+				 */
+				if (perout->phase.sec > perout->period.sec ||
+				    (perout->phase.sec == perout->period.sec &&
+				     perout->phase.nsec > perout->period.nsec)) {
+					err = -ERANGE;
+					break;
+				}
+			}
 		} else if (cmd == PTP_PEROUT_REQUEST) {
 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
 			req.perout.rsv[0] = 0;
-- 
2.25.1