The comment-based filtering in CurOpFailpointHelpers::waitWhileFailPointEnabled (src/mongo/db/curop_failpoint_helpers.cpp) arguably has a logic bug. If the failpoint data has a comment filter but the operation has no comment (opCtx->getComment() is null), the predicate short-circuits and falls through to the nss check, which is typically always true — incorrectly pausing the operation.

Current code:

if (data.hasField("comment") && opCtx->getComment()) {
    return opCtx->getComment()->String() == data.getStringField("comment");
}
return nss.isEmpty() || fpNss.isEmpty() || fpNss == nss;

Suggested change:

if (data.hasField("comment")) {
    return opCtx->getComment() && opCtx->getComment()->String() == data.getStringField("comment");
}
return nss.isEmpty() || fpNss.isEmpty() || fpNss == nss;

Operations without a comment should never match a comment-filtered failpoint.