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https://issues.apache.org/jira/browse/LOG4J2-2980?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17251999#comment-17251999
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Ralph Goers edited comment on LOG4J2-2980 at 12/18/20, 8:47 PM:
----------------------------------------------------------------
I do not know what you are looking at but the current code is
{code:java}
final int length = mac.length >= 6 ? 6 : mac.length;
final int index = mac.length >= 6 ? mac.length - 6 : 0;
final byte[] node = new byte[NODE_SIZE];
node[0] = VARIANT;
node[1] = 0;
for (int i = 2; i < NODE_SIZE; ++i) {
node[i] = 0;
}
System.arraycopy(mac, index, node, 2, length);
{code}
not
{code:java}
System.arraycopy(mac, index, node, index + 2, length);{code}
and the System.arraycopy is now at line 85, not line 81.
As you can see from the code above it already handles the case where the mac
address is longer than 6 bytes.
was (Author: [email protected]):
I do not know what you are looking at but the current code is
{code:java}
final int length = mac.length >= 6 ? 6 : mac.length;
final int index = mac.length >= 6 ? mac.length - 6 : 0;
final byte[] node = new byte[NODE_SIZE];
node[0] = VARIANT;
node[1] = 0;
for (int i = 2; i < NODE_SIZE; ++i) {
node[i] = 0;
}
System.arraycopy(mac, index, node, 2, length);
{code}
not
System.arraycopy(mac, index, node, index + 2, length);
and the System.arraycopy is now at line 85, not line 81.
As you can see from the code above it already handles the case where the mac
address is longer than 6 bytes.
> CLONE - ArrayIndexOutOfBoundsException in the initialization of UuidUtil
> ------------------------------------------------------------------------
>
> Key: LOG4J2-2980
> URL: https://issues.apache.org/jira/browse/LOG4J2-2980
> Project: Log4j 2
> Issue Type: Bug
> Components: Core
> Affects Versions: 2.12.1, 2.13.0, 2.14.0, 2.13.3
> Environment: os : Mac OS
> java: 1.8 (jdk1.8.0_172.jdk)
> none network interfaces connected
> Reporter: Michel Graciano
> Priority: Major
> Fix For: 2.12.1
>
>
> Hi,
> I have cloned the old issue because the patch was not integrated. It should
> be fixed again. Should I send a PR again?
> ---------
> Hi,
> I found a problem in the UuidUtil initialization.
> The code that generate the exception
> {code:java}
> private static Logger log = LogManager.getLogger(MyClass.class);
> {code}
> This code return a ip address of localhost and when the stack is IPv4 return
> 4 bytes but when the default stack is IPv6 it's going to return 16 bytes.
>
> [NetUtils.java#L108|https://github.com/apache/logging-log4j2/blob/da539329d528d979f4dd385a6ebb639793ef37bd/log4j-core/src/main/java/org/apache/logging/log4j/core/util/NetUtils.java#L108]
> {code:java}
> if (mac == null || mac.length == 0) {
> mac = localHost.getAddress();
> }
> {code}
> This is the part that generate the ArrayIndexOutOfBoundsException
>
> [UuidUtil.java#L81|https://github.com/apache/logging-log4j2/blob/da539329d528d979f4dd385a6ebb639793ef37bd/log4j-core/src/main/java/org/apache/logging/log4j/core/util/UuidUtil.java#L81]
> {code:java}
> System.arraycopy(mac, index, node, index + 2, length);{code}
> These 16 bytes will generate a wrong destination index that exceed the length
> of the node array.
> {noformat}
> mac = {byte[16]@3217}
> length = 6
> index = 10
> node = {byte[8]@3222}
> {noformat}
> This is the complete exception
> {code:java}
> java.lang.ExceptionInInitializerError at
> org.apache.logging.log4j.core.util.WatchManager.<init>(WatchManager.java:53)
> at
> org.apache.logging.log4j.core.config.AbstractConfiguration.<init>(AbstractConfiguration.java:135)
> at
> org.apache.logging.log4j.core.config.NullConfiguration.<init>(NullConfiguration.java:32)
> at
> org.apache.logging.log4j.core.LoggerContext.<clinit>(LoggerContext.java:79)
> at
> org.apache.logging.log4j.core.selector.ClassLoaderContextSelector.createContext(ClassLoaderContextSelector.java:171)
> at
> org.apache.logging.log4j.core.selector.ClassLoaderContextSelector.locateContext(ClassLoaderContextSelector.java:145)
> at
> org.apache.logging.log4j.core.selector.ClassLoaderContextSelector.getContext(ClassLoaderContextSelector.java:70)
> at
> org.apache.logging.log4j.core.selector.ClassLoaderContextSelector.getContext(ClassLoaderContextSelector.java:57)
> at
> org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:148)
> at
> org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:45)
> at org.apache.logging.log4j.LogManager.getContext(LogManager.java:194) at
> org.apache.logging.log4j.LogManager.getLogger(LogManager.java:581) at
> cc.arduino.contributions.packages.ContributionInstaller.<clinit>(ContributionInstaller.java:66)
> at processing.app.Base.<init>(Base.java:291) at
> processing.app.Base.main(Base.java:150) Caused by:
> java.lang.ArrayIndexOutOfBoundsException at java.lang.System.arraycopy(Native
> Method) at
> org.apache.logging.log4j.core.util.UuidUtil.<clinit>(UuidUtil.java:81) ... 15
> more
> {code}
> To reproduce the exception you need
> * disconnect every network interface
> * verify that java will use the IPv6 stack -Djava.net.preferIPv4Stack=false
> -Djava.net.preferIPv6Addresses=true
> * Initialize a log of log4j
> I suggest different solution:
> - Remove
> [NetUtils.java#L108|https://github.com/apache/logging-log4j2/blob/da539329d528d979f4dd385a6ebb639793ef37bd/log4j-core/src/main/java/org/apache/logging/log4j/core/util/NetUtils.java#L108]
> and return always null (when the other code fail to init the mac variable )
> because in general the method is called getMacAddress but in that particular
> case will return and IP address
> - Mange the IPv6 case in the static part of the class UuidUtil
> [UuidUtil.java#L81|https://github.com/apache/logging-log4j2/blob/da539329d528d979f4dd385a6ebb639793ef37bd/log4j-core/src/main/java/org/apache/logging/log4j/core/util/UuidUtil.java#L81]
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