iRule regex parsing might cause an indefinite hang

[jszczepanskif5]

Environment

• ACC Version: 1.18
• AS3 Version: N/A
• BIG-IP Version: N/A

Summary

Found in a client UCS archive.

Parsing the following conf file causes ACC to become unresponsive, likely stuck in an infinite loop with 100% CPU usage. The freeze seems to only happen when there's another ltm rule object somewhere after the one with this problematic regex, otherwise we get a regular exception.

Steps To Reproduce

Steps to reproduce the behavior:

1. Convert following config:

ltm rule /tenant_268/application_268/l4j {
when HTTP_REQUEST_DATA {
  set tmpPayload [HTTP::payload]
  set payload [URI::decode $tmpPayload]
  while { $payload ne $tmpPayload } {
    set tmpPayload $payload
    set payload [URI::decode $tmpPayload]
  }

  if {[string tolower $payload] matches_regex {\$\{\s*(j|\$\{).+?\}}} {
    drop
    event disable all
  }
}
}
ltm rule /tenant_268/application_268/foo {

}

2. ACC is now frozen indefinitely.

Note that if we attempt to convert the first iRule without including the second one (or replacing it with any object, e.g. ltm pool), we get the following error:

/app/src/engines/parser.js:150
                if (!(line.trim().startsWith('#') && ruleFlag)) {
                           ^

TypeError: Error parsing input file. Please open an issue at https://github.com/f5devcentral/f5-automation-config-converter/issues and include the following error:
Cannot read properties of undefined (reading 'trim')
    at groupObjects (/app/src/engines/parser.js:150:28)
    at /app/src/engines/parser.js:255:30
    at Array.forEach (<anonymous>)
    at module.exports (/app/src/engines/parser.js:184:28)
    at mainRunner (/app/src/main.js:39:18)
    at main (/app/src/main.js:128:30)

[delgadillo22]

Thank you for the report, I've added this to our internal backlog as CHARON-584 and will get this prioritized.

[p-semenov-f5]

Fixed in 1.19