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Posted to issues@commons.apache.org by "Fabian Meumertzheim (Jira)" <ji...@apache.org> on 2021/03/01 10:44:00 UTC

[jira] [Created] (COMPRESS-569) OutOfMemoryError on a crafted tar file

Fabian Meumertzheim created COMPRESS-569:
--------------------------------------------

             Summary: OutOfMemoryError on a crafted tar file
                 Key: COMPRESS-569
                 URL: https://issues.apache.org/jira/browse/COMPRESS-569
             Project: Commons Compress
          Issue Type: Bug
    Affects Versions: 1.21
            Reporter: Fabian Meumertzheim
         Attachments: TarFileTimeout.java, timeout.tar

Apache Commons Compress at commit
https://github.com/apache/commons-compress/commit/1b7528fbd6295a3958daf1b1114621ee5e40e83c throws an OutOfMemoryError after consuming ~5 minutes of CPU on my
machine on a crafted tar archive that is less than a KiB in size:

Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
at java.base/sun.nio.cs.UTF_8.newDecoder(UTF_8.java:70)
at org.apache.commons.compress.archivers.zip.NioZipEncoding.newDecoder(NioZipEncoding.java:182)
at org.apache.commons.compress.archivers.zip.NioZipEncoding.decode(NioZipEncoding.java:135)
at org.apache.commons.compress.archivers.tar.TarUtils.parseName(TarUtils.java:311)
at org.apache.commons.compress.archivers.tar.TarUtils.parseName(TarUtils.java:275)
at org.apache.commons.compress.archivers.tar.TarArchiveEntry.parseTarHeader(TarArchiveEntry.java:1550)
at org.apache.commons.compress.archivers.tar.TarArchiveEntry.<init>(TarArchiveEntry.java:554)
at org.apache.commons.compress.archivers.tar.TarArchiveEntry.<init>(TarArchiveEntry.java:570)
at org.apache.commons.compress.archivers.tar.TarFile.getNextTarEntry(TarFile.java:250)
at org.apache.commons.compress.archivers.tar.TarFile.<init>(TarFile.java:211)
at org.apache.commons.compress.archivers.tar.TarFile.<init>(TarFile.java:94)
at TarFileTimeout.main(TarFileTimeout.java:22)

I attached both the tar file and a Java reproducer for this issue.

Citing Stefan Bodewig's analysis of this issue:
Your archive contains an entry with a claimed size of -512 bytes. When
TarFile reads entries it tries to skip the content of th entry as it is
only interested in meta data on a first scan and does so by positioning
the input stream right after the data of the current entry. In this case
it positions it 512 bytes backwards right at the start of the current
entry's meta data again. This leads to an infinite loop that reads a new
entry, stores the meta data, repositions the stream and starts over
again. Over time the list of collected meta data eats up all available
memory.



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