tree 625b2c61312f6c516d21714852d7c4eae538565a
parent e76b4f055d8d6a5514f5c67e37ad7a8858b9eed2
author Christopher Faulet <cfaulet@haproxy.com> 1635496695 +0200
committer Christopher Faulet <cfaulet@haproxy.com> 1635512791 +0200

BUG/MEDIUM: resolvers: Don't recursively perform requester unlink

When a requester is unlink from a resolution, by reading the code, we can
have this call chain:

_resolv_unlink_resolution(srv->resolv_requester)
  resolv_detach_from_resolution_answer_items(resolution, requester)
    resolv_srvrq_cleanup_srv(srv)
      _resolv_unlink_resolution(srv->resolv_requester)

A loop on the resolution answer items is performed inside
resolv_detach_from_resolution_answer_items(). But by reading the code, it
seems possible to recursively unlink the same requester.

To avoid any loop at this stage, the requester clean up must be performed
before the call to resolv_detach_from_resolution_answer_items(). This way,
the second call to _resolv_unlink_resolution() does nothing and returns
immediately because the requester was already detached from the resolution.

This patch is related to the issue #1404. It must be backported as far as
2.2.