Merge bitcoin/bitcoin#31486: fuzz: Abort when using global PRNG without re-seed

fae63bf130 fuzz: Clarify that only SeedRandomStateForTest(SeedRand::ZEROS) is allowed (MarcoFalke)
fa18acb457 fuzz: Abort when using global PRNG without re-seed (MarcoFalke)
fa7809aeab fuzz: Add missing SeedRandomStateForTest(SeedRand::ZEROS) (MarcoFalke)

Pull request description:

  This is the first step toward improving fuzz stability and determinism (https://github.com/bitcoin/bitcoin/issues/29018).

  A fuzz target using the global test-only PRNG will now abort if the seed is re-used across fuzz inputs.

  Also, temporarily add `SeedRandomStateForTest(SeedRand::ZEROS)` to all affected fuzz targets. This may slow down the libfuzzer leak detector, but it will disable itself after some time, or it can be disabled explicitly with `-detect_leaks=0`.

  In a follow-up, each affected fuzz target can be stripped of the global random use and a local `RandomMixin` (or similar) can be added instead.

  (Can be tested by removing any one of the re-seed calls and observing a fuzz abort)

ACKs for top commit:
  hodlinator:
    ACK fae63bf130
  dergoegge:
    utACK fae63bf130
  marcofleon:
    Tested ACK fae63bf130

Tree-SHA512: 4a0db69af7f715408edf4f8b08b44f34ce12ee2c79d33b336ad19a6e6bd079c4ff7c971af0a3efa428213407c1171f4e2837ec6a2577086c2f94cd15618a0892
This commit is contained in:
Ryan Ofsky
2024-12-17 12:33:41 -05:00
39 changed files with 131 additions and 7 deletions

View File

@@ -108,6 +108,9 @@ static void ExitFailure(std::string_view str_err)
BasicTestingSetup::BasicTestingSetup(const ChainType chainType, TestOpts opts)
: m_args{}
{
if constexpr (!G_FUZZING) {
SeedRandomForTest(SeedRand::FIXED_SEED);
}
m_node.shutdown_signal = &m_interrupt;
m_node.shutdown_request = [this]{ return m_interrupt(); };
m_node.args = &gArgs;
@@ -139,8 +142,6 @@ BasicTestingSetup::BasicTestingSetup(const ChainType chainType, TestOpts opts)
}
}
SeedRandomForTest(SeedRand::FIXED_SEED);
const std::string test_name{G_TEST_GET_FULL_NAME ? G_TEST_GET_FULL_NAME() : ""};
if (!m_node.args->IsArgSet("-testdatadir")) {
// To avoid colliding with a leftover prior datadir, and to allow