The logMessageInterval field has an improbable range from 2^-128 to 2^127
seconds. The extreme ends cause an integer overflow in the calculation
of the "foreign master time window". Buggy or mis-configured foreign
masters advertising extreme values will cause incorrect announce message
aging.
This patch fixes the issue by adding thresholds for the bogus extremes.
Signed-off-by: Richard Cochran <richardcoch...@gmail.com>
---
port.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/port.c b/port.c
index 3984b78..ef2686d 100644
--- a/port.c
+++ b/port.c
@@ -163,10 +163,15 @@ static int msg_current(struct ptp_message *m, struct
timespec now)
t1 = m->ts.host.tv_sec * NSEC2SEC + m->ts.host.tv_nsec;
t2 = now.tv_sec * NSEC2SEC + now.tv_nsec;
- if (m->header.logMessageInterval < 0)
+ if (m->header.logMessageInterval < -63) {
+ tmo = 0;
+ } else if (m->header.logMessageInterval > 31) {
+ tmo = INT64_MAX;
+ } else if (m->header.logMessageInterval < 0) {
tmo = 4LL * NSEC2SEC / (1 << -m->header.logMessageInterval);
- else
+ } else {
tmo = 4LL * (1 << m->header.logMessageInterval) * NSEC2SEC;
+ }
return t2 - t1 < tmo;
}
--
2.1.4
------------------------------------------------------------------------------
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