Stackoverflow on Elasticsearch file indexation with ingest-attachment

Elastic Stack Elasticsearch
4

I have tested most recently version (7.9.3), but same problem occurs.

Seeing the log with more attention, the problem occurs on PDPageTree wich comes from Apache PDFBox (wich I'm investigating now).

[2020-10-28T14:52:27,849][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [es-node] fatal error in thread [elasticsearch[es-node][write][T#7]], exiting
java.lang.StackOverflowError: null
	at java.util.regex.Pattern$BmpCharPredicate.lambda$union$2(Pattern.java:5692) ~[?:?]
	at java.util.regex.Pattern$BmpCharProperty.match(Pattern.java:4019) ~[?:?]
	at java.util.regex.Pattern$GroupHead.match(Pattern.java:4855) ~[?:?]
	at java.util.regex.Pattern$BranchConn.match(Pattern.java:4763) ~[?:?]
	at java.util.regex.Pattern$GroupTail.match(Pattern.java:4886) ~[?:?]
	at java.util.regex.Pattern$BmpCharProperty.match(Pattern.java:4020) ~[?:?]
	at java.util.regex.Pattern$GroupHead.match(Pattern.java:4855) ~[?:?]
	at java.util.regex.Pattern$Branch.match(Pattern.java:4800) ~[?:?]
	at java.util.regex.Pattern$Branch.match(Pattern.java:4798) ~[?:?]
	at java.util.regex.Pattern$Branch.match(Pattern.java:4798) ~[?:?]
	at java.util.regex.Pattern$BranchConn.match(Pattern.java:4763) ~[?:?]
	at java.util.regex.Pattern$GroupTail.match(Pattern.java:4886) ~[?:?]
	at java.util.regex.Pattern$BmpCharPropertyGreedy.match(Pattern.java:4394) ~[?:?]
	at java.util.regex.Pattern$GroupHead.match(Pattern.java:4855) ~[?:?]
	at java.util.regex.Pattern$Branch.match(Pattern.java:4800) ~[?:?]
	at java.util.regex.Pattern$BranchConn.match(Pattern.java:4763) ~[?:?]
	at java.util.regex.Pattern$GroupTail.match(Pattern.java:4886) ~[?:?]
	at java.util.regex.Pattern$BmpCharProperty.match(Pattern.java:4020) ~[?:?]
	at java.util.regex.Pattern$BmpCharPropertyGreedy.match(Pattern.java:4394) ~[?:?]
	at java.util.regex.Pattern$GroupHead.match(Pattern.java:4855) ~[?:?]
	at java.util.regex.Pattern$Branch.match(Pattern.java:4800) ~[?:?]
	at java.util.regex.Pattern$BmpCharProperty.match(Pattern.java:4020) ~[?:?]
	at java.util.regex.Pattern$Start.match(Pattern.java:3673) ~[?:?]
	at java.util.regex.Matcher.search(Matcher.java:1729) ~[?:?]
	at java.util.regex.Matcher.find(Matcher.java:773) ~[?:?]
	at java.util.Formatter.parse(Formatter.java:2702) ~[?:?]
	at java.util.Formatter.format(Formatter.java:2655) ~[?:?]
	at java.util.Formatter.format(Formatter.java:2609) ~[?:?]
	at java.lang.String.format(String.java:3292) ~[?:?]
	at java.util.logging.SimpleFormatter.format(SimpleFormatter.java:176) ~[?:?]
	at java.util.logging.StreamHandler.publish(StreamHandler.java:199) ~[?:?]
	at java.util.logging.ConsoleHandler.publish(ConsoleHandler.java:95) ~[?:?]
	at java.util.logging.Logger.log(Logger.java:979) ~[?:?]
	at java.util.logging.Logger.doLog(Logger.java:1006) ~[?:?]
	at java.util.logging.Logger.logp(Logger.java:1172) ~[?:?]
	at org.apache.commons.logging.impl.Jdk14Logger.log(Jdk14Logger.java:87) ~[?:?]
	at org.apache.commons.logging.impl.Jdk14Logger.warn(Jdk14Logger.java:260) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree.getKids(PDPageTree.java:159) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree.access$200(PDPageTree.java:41) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:183) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]
	at org.apache.pdfbox.pdmodel.PDPageTree$PageIterator.enqueueKids(PDPageTree.java:186) ~[?:?]

But I think that problems that come from plugins used by ES should not affect the integrity of the node. Maybe it would be interesting to have some treat to just return an error in the request instead of killing the entire node. There is a flag that can be set in the pipelines (ignore_failure), but this did not solve this situation. Don't you think so?