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From 2b0874a8a0ff4bced5da0c25a4b3f3fbd2595e23 Mon Sep 17 00:00:00 2001
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From: Michal Sekletar <msekleta@redhat.com>
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Date: Wed, 1 May 2019 15:58:44 +0200
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Subject: [PATCH] udev: check age against both timeouts to prevent integer
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 wraparound
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If we get back to while loop after timeout_warn (roughly 60s)
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expired for the first time, but before age of the event is larger than
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second timeout (roughly 120s) we would try to recompute timeout_warn
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again. Previously the following code,
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if (timeout_warn_usec > 0)
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        timeout_warn = ((timeout_warn_usec - age_usec) / USEC_PER_MSEC) + MSEC_PER_SEC;
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would cause an integer wraparound because (timeout_warn_usec - age_usec)
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is negative however both timeout_warn_usec and age_usec are
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unsigned.
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This can happen if we get SIGTERM from the main daemon while waiting in
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the second poll(), i.e. after timeout_warn already expired, because on
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SIGTERM we just take a note of that happening in event->sigterm and
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continue.
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Related: #1697909
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---
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 src/udev/udev-event.c | 2 +-
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 1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/src/udev/udev-event.c b/src/udev/udev-event.c
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index 07b82d093e..5550ec93de 100644
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--- a/src/udev/udev-event.c
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+++ b/src/udev/udev-event.c
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@@ -559,7 +559,7 @@ static int spawn_wait(struct udev_event *event,
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                         usec_t age_usec;
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                         age_usec = now(CLOCK_MONOTONIC) - event->birth_usec;
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-                        if (age_usec >= timeout_usec)
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+                        if (age_usec >= timeout_usec || age_usec >= timeout_warn_usec)
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                                 timeout = 1000;
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                         else {
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                                 if (timeout_warn_usec > 0)