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  1. C Driver
  2. CDRIVER-2605

OpenSSL thread and id callbacks should be unset independently

    • Type: Icon: Bug Bug
    • Resolution: Fixed
    • Priority: Icon: Major - P3 Major - P3
    • 1.10.0
    • Affects Version/s: 1.9.3
    • Component/s: None
    • None
    • Environment:
      PHP (mongodb, curl, and openssl extensions), OpenSSL 1.0.2m

      PHPC-1158 describes a situation where multiple PHP extensions interacting with OpenSSL resulted in a dangling function pointer to libmongoc's thread id callback being left in place. This ultimately produced a segfault during cURL's shutdown routines, which also interacted with OpenSSL and attempted to invoke that callback after libmongoc had already been unloaded (i.e. dlclose()).

      This previously came up in CDRIVER-555. The fix (746d250, released in 1.1.2) introduced the logic we see today that checks the locking callback before assigning or unsetting libmongoc's callbacks.

      I propose that _mongoc_openssl_thread_cleanup() be improved to clear the locking and id callbacks independently if either is still assigned to the libmongoc function. _mongoc_openssl_thread_startup() can be left as-is and only assign locking and id callbacks if the locking callback is currently unset.

            Assignee:
            jmikola@mongodb.com Jeremy Mikola
            Reporter:
            jmikola@mongodb.com Jeremy Mikola
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              Created:
              Updated:
              Resolved: