Merge bitcoin/bitcoin#21892: fuzz: Avoid excessively large min fee rate in tx_pool

99993f066405863c66ccaec0a8427129f4515768 fuzz: Avoid excessively large min fee rate in tx_pool (MarcoFalke)

Pull request description:

  Any fee rate above 1 BTC / kvB is clearly nonsense, so no need to fuzz this.

  Hopefully fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34078

ACKs for top commit:
  practicalswift:
    cr ACK 99993f066405863c66ccaec0a8427129f4515768: patch looks correct despite no `fa` prefix in commit hash

Tree-SHA512: bd3651d354b13d889ad1708d2b385ad0479de036de74a237346eefad5dbfb1df76ec02b55ec00487ec598657ef6102f992302b14c4e47f913a9962f81f4157e6

3 files changed, 7 insertions, 5 deletions

diff --git a/src/test/fuzz/tx_pool.cpp b/src/test/fuzz/tx_pool.cpp
index 59229987ba..068e207118 100644
--- a/src/test/fuzz/tx_pool.cpp
+++ b/src/test/fuzz/tx_pool.cpp
@@ -84,7 +84,7 @@ void Finish(FuzzedDataProvider& fuzzed_data_provider, MockedTxPool& tx_pool, CCh
     {
         BlockAssembler::Options options;
         options.nBlockMaxWeight = fuzzed_data_provider.ConsumeIntegralInRange(0U, MAX_BLOCK_WEIGHT);
-        options.blockMinFeeRate = CFeeRate{ConsumeMoney(fuzzed_data_provider)};
+        options.blockMinFeeRate = CFeeRate{ConsumeMoney(fuzzed_data_provider, /* max */ COIN)};
         auto assembler = BlockAssembler{chainstate, *static_cast<CTxMemPool*>(&tx_pool), ::Params(), options};
         auto block_template = assembler.CreateNewBlock(CScript{} << OP_TRUE);
         Assert(block_template->block.vtx.size() >= 1);
diff --git a/src/test/fuzz/util.cpp b/src/test/fuzz/util.cpp
index 574b694d1a..bcf0b0ce72 100644
--- a/src/test/fuzz/util.cpp
+++ b/src/test/fuzz/util.cpp
@@ -217,6 +217,11 @@ void FillNode(FuzzedDataProvider& fuzzed_data_provider, CNode& node, bool init_v
     }
 }
 
+CAmount ConsumeMoney(FuzzedDataProvider& fuzzed_data_provider, const std::optional<CAmount>& max) noexcept
+{
+    return fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(0, max.value_or(MAX_MONEY));
+}
+
 int64_t ConsumeTime(FuzzedDataProvider& fuzzed_data_provider, const std::optional<int64_t>& min, const std::optional<int64_t>& max) noexcept
 {
     // Avoid t=0 (1970-01-01T00:00:00Z) since SetMockTime(0) disables mocktime.
diff --git a/src/test/fuzz/util.h b/src/test/fuzz/util.h
index 1a83f7a57a..48b7877896 100644
--- a/src/test/fuzz/util.h
+++ b/src/test/fuzz/util.h
@@ -123,10 +123,7 @@ template <typename WeakEnumType, size_t size>
     return static_cast<opcodetype>(fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(0, MAX_OPCODE));
 }
 
-[[nodiscard]] inline CAmount ConsumeMoney(FuzzedDataProvider& fuzzed_data_provider) noexcept
-{
-    return fuzzed_data_provider.ConsumeIntegralInRange<CAmount>(0, MAX_MONEY);
-}
+[[nodiscard]] CAmount ConsumeMoney(FuzzedDataProvider& fuzzed_data_provider, const std::optional<CAmount>& max = std::nullopt) noexcept;
 
 [[nodiscard]] int64_t ConsumeTime(FuzzedDataProvider& fuzzed_data_provider, const std::optional<int64_t>& min = std::nullopt, const std::optional<int64_t>& max = std::nullopt) noexcept;