go-ethereum/tests/fuzzers
Csaba Kiraly 59ad40e562
eth: check for tx on chain as well (#33607)
The fetcher should not fetch transactions that are already on chain.
Until now we were only checking in the txpool, but that does not have
the old transaction. This was leading to extra fetches of transactions
that were announced by a peer but are already on chain.

Here we extend the check to the chain as well.
2026-02-24 11:21:03 +01:00
..
bls12381 tests/fuzzers/bls12381: fix error message in fuzzCrossG2Add (#31113) 2025-02-04 07:09:06 +01:00
bn256 tests/fuzzers: added bn marshaling fuzzers (#32053) 2025-06-17 23:02:36 +02:00
difficulty all: update license comments and AUTHORS (#31133) 2025-02-05 23:01:17 +01:00
rangeproof tests/fuzzers: remove unused field from kv struct in rangeproof fuzzer (#33447) 2025-12-19 09:13:00 +08:00
secp256k1 crypto: use decred secp256k1 directly (#30595) 2024-10-15 11:49:08 +03:00
txfetcher eth: check for tx on chain as well (#33607) 2026-02-24 11:21:03 +01:00
README.md all: fix typos in comments (#21118) 2020-05-25 10:21:28 +02:00

Fuzzers

To run a fuzzer locally, you need go-fuzz installed.

First build a fuzzing-binary out of the selected package:

(cd ./rlp && CGO_ENABLED=0 go-fuzz-build .)

That command should generate a rlp-fuzz.zip in the rlp/ directory. If you are already in that directory, you can do

[user@work rlp]$ go-fuzz
2019/11/26 13:36:54 workers: 6, corpus: 3 (3s ago), crashers: 0, restarts: 1/0, execs: 0 (0/sec), cover: 0, uptime: 3s
2019/11/26 13:36:57 workers: 6, corpus: 3 (6s ago), crashers: 0, restarts: 1/0, execs: 0 (0/sec), cover: 1054, uptime: 6s
2019/11/26 13:37:00 workers: 6, corpus: 3 (9s ago), crashers: 0, restarts: 1/8358, execs: 25074 (2786/sec), cover: 1054, uptime: 9s
2019/11/26 13:37:03 workers: 6, corpus: 3 (12s ago), crashers: 0, restarts: 1/8497, execs: 50986 (4249/sec), cover: 1054, uptime: 12s
2019/11/26 13:37:06 workers: 6, corpus: 3 (15s ago), crashers: 0, restarts: 1/9330, execs: 74640 (4976/sec), cover: 1054, uptime: 15s
2019/11/26 13:37:09 workers: 6, corpus: 3 (18s ago), crashers: 0, restarts: 1/9948, execs: 99482 (5527/sec), cover: 1054, uptime: 18s
2019/11/26 13:37:12 workers: 6, corpus: 3 (21s ago), crashers: 0, restarts: 1/9428, execs: 122568 (5836/sec), cover: 1054, uptime: 21s
2019/11/26 13:37:15 workers: 6, corpus: 3 (24s ago), crashers: 0, restarts: 1/9676, execs: 145152 (6048/sec), cover: 1054, uptime: 24s
2019/11/26 13:37:18 workers: 6, corpus: 3 (27s ago), crashers: 0, restarts: 1/9855, execs: 167538 (6205/sec), cover: 1054, uptime: 27s
2019/11/26 13:37:21 workers: 6, corpus: 3 (30s ago), crashers: 0, restarts: 1/9645, execs: 192901 (6430/sec), cover: 1054, uptime: 30s
2019/11/26 13:37:24 workers: 6, corpus: 3 (33s ago), crashers: 0, restarts: 1/9967, execs: 219294 (6645/sec), cover: 1054, uptime: 33s

Otherwise:

go-fuzz -bin ./rlp/rlp-fuzz.zip

Notes

Once a 'crasher' is found, the fuzzer tries to avoid reporting the same vector twice, so stores the fault in the suppressions folder. Thus, if you e.g. make changes to fix a bug, you should remove all data from the suppressions-folder, to verify that the issue is indeed resolved.

Also, if you have only one and the same exit-point for multiple different types of test, the suppression can make the fuzzer hide different types of errors. So make sure that each type of failure is unique (for an example, see the rlp fuzzer, where a counter i is used to differentiate between failures:

		if !bytes.Equal(input, output) {
			panic(fmt.Sprintf("case %d: encode-decode is not equal, \ninput : %x\noutput: %x", i, input, output))
		}