Describe the bug, including details regarding any error messages, version, and platform.

There is a potential integer overflow in PoolBuffer::Resize and PoolBuffer::Reserve when rounding up the desired capacity to a multiple of 64.

This was found by OSS-Fuzz: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=71200

Component(s)

C++, Continuous Integration