3 Nightly 84.0a1 crashes on 2 installations, the oldest build ID is 20201028092421.

Could this be from bug 1670985?

Crash report: https://crash-stats.mozilla.org/report/index/ae3f585e-0cbe-45dc-889f-60f940201101

Reason: EXCEPTION_ACCESS_VIOLATION

Top 10 frames of crashing thread:

0 mozglue.dll arena_dalloc memory/build/mozjemalloc.cpp:3364
1 xul.dll core::ptr::drop_in_place<std::collections::hash::set::HashSet<alloc::vec::Vec<u8>, std::collections::hash::map::RandomState>> ../18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/core/src/ptr/mod.rs:184
2 xul.dll cert_storage::SecurityState::load_crlite_stash security/manager/ssl/cert_storage/src/lib.rs:458
3 xul.dll cert_storage::{{impl}}::run<tuple<>, closure-0> security/manager/ssl/cert_storage/src/lib.rs:1121
4 xul.dll moz_task::{{impl}}::allocate::Run xpcom/rust/moz_task/src/lib.rs:212
5 xul.dll mozilla::TaskQueue::Runner::Run xpcom/threads/TaskQueue.cpp:158
6 xul.dll nsThreadPool::Run xpcom/threads/nsThreadPool.cpp:299
7 xul.dll nsThread::ProcessNextEvent xpcom/threads/nsThread.cpp:1197
8 xul.dll mozilla::ipc::MessagePumpForNonMainThreads::Run ipc/glue/MessagePump.cpp:302
9 xul.dll MessageLoop::RunHandler ipc/chromium/src/base/message_loop.cc:327

I doubt it - bug 1670985 wouldn't have changed how often or with which inputs we hit this code. Looking at the stack traces, this is happening when we clear a HashMap. There's no tricky data ownership issues here, so either this is a bug in rust's standard library or this is bad RAM.

Bug 1678762 probably addressed this.