Anton Klarén created LOG4J2-3087:
------------------------------------
Summary: JsonTemplateLayout can produces invalid JSON with
timestamp+pattern
Key: LOG4J2-3087
URL: https://issues.apache.org/jira/browse/LOG4J2-3087
Project: Log4j 2
Issue Type: Bug
Components: JsonTemplateLayout
Affects Versions: 2.14.1, 2.14.0
Reporter: Anton Klarén
There is a "race" when constructing a *{{JsonTemplateLayout}}* that can produce
invalid JSON.
In the constructor of *{{FormatResolverContext}}* the
*{{formattedTimestampBuilder}}* is populated with a formated, but unquoted,
timestamp based on the current time. Later in *{{FormatResolver.resolve()}}* we
check if the log event matches the current time and use the cached value to
*{{jsonWriter.writeRawString()}}*, which can be unquoted if the layout and log
event was created in the same millisecond.
Easy to reproduce with:
{code:java}
package org.apache.logging.log4j.layout.template.json;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.DefaultConfiguration;
import org.junit.jupiter.api.RepeatedTest;
class JsonTemplateLayoutTimestampTest
{
private static final Configuration CONFIGURATION = new
DefaultConfiguration();
@RepeatedTest( 20 )
void test_timestamp_pattern_race() {
final JsonTemplateLayout layout = JsonTemplateLayout
.newBuilder()
.setConfiguration(CONFIGURATION)
.setEventTemplate("{\"t\":{\"$resolver\":\"timestamp\",\"pattern\":{\"format\":\"yyyy-MM-dd\"}}}")
.build();
final LogEvent logEvent = LogEventFixture.createLiteLogEvents(1).get(0);
final String json = layout.toSerializable(logEvent);
System.out.println(json);
}
}
{code}
which can print
{code:json}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":"2021-05-04"}
{"t":2021-05-04}
{"t":2021-05-04}
{"t":2021-05-04}
{"t":2021-05-04}
{code}
I'm working on a fix.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
