I pushed a few commits in master branch trying to address this issue. I haven't implemented the memory mod stats, but as I could see in the code, it didn't seem to be protected for races on accessing the shm fragments.
You would need to test with master branch or by using patches from the next commits:
* aa458a62f034c2cb57639bdc713ed3c51b0292c7 * 761eb0616fea2a859a2c0abb652b22feb6f59859 * 9645be245f899fa8ae11a6be045d2ef83fd66bf5