We used to pass the parent object to callbacks, but this isn't safe. The
object is in the middle of being destroyed, so the object's
invariants won't hold. We can't remove the parameters, but pass in NULL
instead.
This also has the side effect of making it possible to manage
CRYPTO_EX_DATA lifetime in its destructor, because we won't need to find
some handle back to the parent object. It also means that defensively
clearing fields in BIO destroy callbacks, while harmless, is more
obviously unnecessary.
Update-Note: CRYPTO_EX_free is no longer passed the parent object. We do
not expect any callers to be impacted. Callers that were impacted
probably had some object lifetime bug already.
Fixed: 412707574
Change-Id: Idda889898a9eca3b59e3200ba1d5b4f2e62f2d37
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/79607
Reviewed-by: Adam Langley <agl@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
David Benjamin
035e720641