- Fix integer overflow in infra-cache-max-rtt calculation.

  Thanks to Qifan Zhang, Palo Alto Networks, for the report.

diff --git a/doc/Changelog b/doc/Changelog
index 2311deedce85b8572b658ac68b50c7e45da9a6b1..a87ca884966e33b3d74d1d6190131fbdf3ca7539 100644 (file)
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -25,6 +25,8 @@
          lookups are in progress, for a primary name. Also after the
          change, it no longer picks up the old results. Thanks to
          Qifan Zhang, Palo Alto Networks, for the report.
+       - Fix integer overflow in infra-cache-max-rtt calculation.
+         Thanks to Qifan Zhang, Palo Alto Networks, for the report.
 
 12 June 2026: Wouter
        - Fix that for auth-zone and rpz zones the allow-notify

diff --git a/util/config_file.c b/util/config_file.c
index e026047ab317090ea34dac68c9cc4385db858bc2..428633b6c59412c2151f8d5a79b76ab134490beb 100644 (file)
--- a/util/config_file.c
+++ b/util/config_file.c
@@ -46,6 +46,7 @@
 #ifdef HAVE_TIME_H
 #include <time.h>
 #endif
+#include <limits.h>
 #include "util/log.h"
 #include "util/configyyrename.h"
 #include "util/config_file.h"
@@ -533,7 +534,11 @@ probe_maxrto(int useful_server_top_timeout) {
 int config_apply_max_rtt(int max_rtt)
 {
        USEFUL_SERVER_TOP_TIMEOUT = max_rtt;
-       BLACKLIST_PENALTY = max_rtt*4;
+       BLACKLIST_PENALTY =
+#ifdef INT_MAX
+               (max_rtt > INT_MAX/4) ? INT_MAX :
+#endif
+               max_rtt*4;
        PROBE_MAXRTO = probe_maxrto(max_rtt);
        return max_rtt;
 }