miner: Avoid stack-use-after-return in validationinterface

This is achieved by switching to a shared_ptr.

Also, switch the validationinterfaces in the tests to use shared_ptrs
for the same reason.

Github-Pull: #18742
Rebased-From: 7777f2a4bb1f9d843bc50a4e35085cfbb2808780

1 files changed, 6 insertions, 6 deletions

diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index da9d583fa7..94590e0da4 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -724,7 +724,7 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
     return result;
 }
 
-class submitblock_StateCatcher : public CValidationInterface
+class submitblock_StateCatcher final : public CValidationInterface
 {
 public:
     uint256 hash;
@@ -792,17 +792,17 @@ static UniValue submitblock(const JSONRPCRequest& request)
     }
 
     bool new_block;
-    submitblock_StateCatcher sc(block.GetHash());
-    RegisterValidationInterface(&sc);
+    auto sc = std::make_shared<submitblock_StateCatcher>(block.GetHash());
+    RegisterSharedValidationInterface(sc);
     bool accepted = ProcessNewBlock(Params(), blockptr, /* fForceProcessing */ true, /* fNewBlock */ &new_block);
-    UnregisterValidationInterface(&sc);
+    UnregisterSharedValidationInterface(sc);
     if (!new_block && accepted) {
         return "duplicate";
     }
-    if (!sc.found) {
+    if (!sc->found) {
         return "inconclusive";
     }
-    return BIP22ValidationResult(sc.state);
+    return BIP22ValidationResult(sc->state);
 }
 
 static UniValue submitheader(const JSONRPCRequest& request)