dag: check rlen is a valid length

[sfd]

Ticket: 8804

(cherry picked from commit a37b75a)

Contribution style:

• I have read the contributing guide lines at
  https://docs.suricata.io/en/latest/devguide/contributing/contribution-process.html

Our Contribution agreements:

• I have signed the Open Information Security Foundation contribution agreement at
  https://suricata.io/about/contribution-agreement/ (note: this is only required once)

Changes (if applicable):

• I have updated the User Guide (in doc/userguide/) to reflect the changes made
• I have updated the JSON schema (in etc/schema.json) to reflect all logging changes
  (including schema descriptions)
• I have created a ticket at
  https://redmine.openinfosecfoundation.org/projects/suricata/issues

Link to ticket: https://redmine.openinfosecfoundation.org/issues/8804

Describe changes:

• Backport from Ticket 8797 to main-8.0.x
• Add check to rlen value read from ERF record to avoid potential infinite loop, must be >= dag_record_length (16).
• Similar check exists in source_erf_file already.

Provide values to any of the below to override the defaults.

• To use a Suricata-Verify or Suricata-Update pull request,
  link to the pull request in the respective _BRANCH variable.
• Leave unused overrides blank or remove.

SV_REPO=
SV_BRANCH=
SU_REPO=
SU_BRANCH=

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.65%. Comparing base (27ff8c8) to head (b91ef71).

Additional details and impacted files

@@              Coverage Diff               @@
##           main-8.0.x   #16018      +/-   ##
==============================================
- Coverage       81.68%   81.65%   -0.03%     
==============================================
  Files            1016     1016              
  Lines          276981   276981              
==============================================
- Hits           226245   226181      -64     
- Misses          50736    50800      +64     

Flag	Coverage Δ
fuzzcorpus	63.83% <ø> (-0.08%)	⬇️
livemode	18.63% <ø> (-0.05%)	⬇️
netns	20.15% <ø> (-0.01%)	⬇️
pcap	44.45% <ø> (-0.05%)	⬇️
suricata-verify	65.15% <ø> (-0.06%)	⬇️
unittests	58.60% <ø> (ø)

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[sfd]

Thanks @victorjulien, please merge as appropriate

[victorjulien]

Merged in #16042, thanks!