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From: Pekka Helenius <fincer89@hotmail.com>
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Date: Thu, 13 Aug 2020 21:55:20 +0300
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Subject: Cast constraint median time value to unsigned long. Fixes overflow on 32-bit systems.
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--- a/src/constraint.c 2020-08-03 23:43:48.584926017 +0300
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+++ b/src/constraint.c 2020-08-13 21:54:44.579053808 +0300
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@@ -941,7 +941,14 @@ constraint_update(void)
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/* calculate median */
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i = cnt / 2;
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if (cnt % 2 == 0)
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- conf->constraint_median = (values[i - 1] + values[i]) / 2;
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+
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+ /*
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+ * Casting to unsigned long (ul) is required on 32-bit systems.
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+ * Otherwise, the summed value exceed the maximum 32-bit time_t value and overflows
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+ * before divide operation, resulting to a great negative value which again leads to
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+ * an invalid constraint_median value.
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+ */
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+ conf->constraint_median = ( (unsigned long)(values[i - 1] + values[i]) ) / 2;
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else
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conf->constraint_median = values[i];
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