19772 FIX Oracle instance uptime check: handle negative uptime values

Crash-Group-ID: 3653
Jira: CMK-33556
Change-Id: Ifa37d181a46d576807a5ddf5670fa80bfcbbef3e

Author: otAAAh

.werks/19772.md

@@ -0,0 +1,19 @@
+[//]: # (werk v3)
+# Oracle instance uptime check: handle negative uptime values
+
+key        | value
+---------- | ---
+date       | 2026-04-14T12:00:00+00:00
+version    | 2.6.0b1
+class      | fix
+edition    | community
+component  | checks
+level      | 1
+compatible | yes
+
+The Oracle instance uptime check could crash with a `ValueError: Cannot render
+negative timespan` when the Oracle database reported a negative uptime value.
+This can happen due to clock synchronization issues or Oracle-internal anomalies.
+
+The check now handles negative uptime values gracefully by reporting a warning
+instead of crashing.

cmk/plugins/oracle/agent_based/oracle_instance_check.py

@@ -194,6 +194,13 @@ def check_oracle_instance_uptime(
     if data.up_seconds is None:
         return
 
+    if data.up_seconds < 0:
+        yield Result(
+            state=State.WARN,
+            summary=f"Uptime: invalid negative value ({data.up_seconds}s)",
+        )
+        return
+
     yield Result(
         state=State.OK, summary=f"Up since {render.datetime(time.time() - data.up_seconds)}"
     )

tests/unit/cmk/plugins/oracle/agent_based/test_oracle_instance_uptime.py

@@ -90,11 +90,10 @@ def test_check_oracle_instance_uptime_error() -> None:
         )
 
 
-@pytest.mark.xfail(strict=True, reason="Crash group 3653: ValueError on negative up_seconds")
 def test_check_oracle_instance_uptime_negative_uptime() -> None:
-    """Negative up_seconds from Oracle causes ValueError in render.timespan."""
+    """Negative up_seconds from Oracle should produce a warning, not crash."""
     with time_machine.travel(datetime.datetime.fromtimestamp(1643360266, tz=ZoneInfo("UTC"))):
-        results = list(
+        assert list(
             check_plugin_oracle_instance_uptime.check_function(
                 item="OBIP",
                 params={},
@@ -108,9 +107,9 @@ def test_check_oracle_instance_uptime_negative_uptime() -> None:
                     ),
                 },
             )
-        )
-        # Should not crash — negative uptime is an anomaly but should be handled gracefully
-        assert any(isinstance(r, Result) for r in results)
+        ) == [
+            Result(state=State.WARN, summary="Uptime: invalid negative value (-6689s)"),
+        ]
 
 
 def test_check_oracle_instance_uptime_pdb_mounted() -> None: