From 2b0874a8a0ff4bced5da0c25a4b3f3fbd2595e23 Mon Sep 17 00:00:00 2001

From: Michal Sekletar <msekleta@redhat.com>

Date: Wed, 1 May 2019 15:58:44 +0200

Subject: [PATCH] udev: check age against both timeouts to prevent integer

 wraparound

If we get back to while loop after timeout_warn (roughly 60s)

expired for the first time, but before age of the event is larger than

second timeout (roughly 120s) we would try to recompute timeout_warn

again. Previously the following code,

if (timeout_warn_usec > 0)

        timeout_warn = ((timeout_warn_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;

would cause an integer wraparound because (timeout_warn_usec - age_usec)

is negative however both timeout_warn_usec and age_usec are

unsigned.

This can happen if we get SIGTERM from the main daemon while waiting in

the second poll(), i.e. after timeout_warn already expired, because on

SIGTERM we just take a note of that happening in event->sigterm and

continue.

Related: #1697909

---

 src/udev/udev-event.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/udev/udev-event.c b/src/udev/udev-event.c

index 07b82d093e..5550ec93de 100644

--- a/src/udev/udev-event.c

+++ b/src/udev/udev-event.c

@@ -559,7 +559,7 @@ static int spawn_wait(struct udev_event *event,

                         usec_t age_usec;

                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;

-                        if (age_usec >= timeout_usec)

+                        if (age_usec >= timeout_usec || age_usec >= timeout_warn_usec)

                                 timeout = 1000;

                         else {

                                 if (timeout_warn_usec > 0)