rgw: KMS Cache: Reset Reaper State in Async+Threaded

Reset reaper state to monostate in the async and threaded case.
Fixes a possible use after free in the async reaper case.

Signed-off-by: Marcel Lauhoff <marcel.lauhoff@clyso.com>
On-behalf-of: SAP marcel.lauhoff@sap.com

diff --git a/src/rgw/rgw_kms_cache.cc b/src/rgw/rgw_kms_cache.cc
index c221d8bb25e8abd3889d0e6a702c07d83336bb1d..334487c33ebe01d6e5a2c7f1408ff49059555a79 100644 (file)
--- a/src/rgw/rgw_kms_cache.cc
+++ b/src/rgw/rgw_kms_cache.cc
@@ -148,7 +148,7 @@ void KMSCache::stop_ttl_reaper() {
   ceph_assert(cache);
   std::visit(
       fu2::overload(
-          [](const std::monostate& mono) {},
+          [](const std::monostate&) {},
           [](AsyncState& async_state) {
             boost::asio::dispatch(
                 async_state.strand,
@@ -161,8 +161,9 @@ void KMSCache::stop_ttl_reaper() {
               if (e.code() != std::future_errc::no_state) throw;
             }
           },
-          [&](const std::jthread&) { reaper_state.emplace<std::monostate>(); }),
+          [](const std::jthread&) {}),
       reaper_state);
+  reaper_state.emplace<std::monostate>();
 }
 
 void KMSCache::clear_cache() const {