Rather than crashing the entire node on invalid pubkey, check the
validity of the pubkey in decode_n, and return an error if invalid.
Detected by libFuzzer:
==265599== ERROR: libFuzzer: deadly signal
#7 abort
#8 bolt11_decode common/bolt11.c:999:4
Invalid recovery IDs cause
secp256k1_ecdsa_recoverable_signature_parse_compact to abort, which
crashes the entire node. We should return an error instead.
Detected by libFuzzer:
[libsecp256k1] illegal argument: recid >= 0 && recid <= 3
Remove the assertion so that an error is returned for invalid bech32.
An error is preferable to crashing the entire node if there's an extra
"lightning:" prefix:
$ lightning-cli pay "lightning:lightning:"
Node log:
pay: common/bolt11.c:718: bolt11_decode_nosig: Assertion `!has_lightning_prefix(str)' failed.
pay: FATAL SIGNAL 6
...
INFO plugin-pay: Killing plugin: exited during normal operation
**BROKEN** plugin-pay: Plugin marked as important, shutting down lightningd
If both databits and *data_len are 0, pull_uint return uninitialized
stack memory in *val.
Detected by valgrind and UBSan.
valgrind:
==173904== Use of uninitialised value of size 8
==173904== __sanitizer_cov_trace_cmp8
==173904== decode_c (bolt11.c:292)
==173904== bolt11_decode_nosig (bolt11.c:877)
UBSan:
common/bolt11.c:79:29: runtime error: shift exponent 64 is too large for 64-bit type 'uint64_t' (aka 'unsigned long')
Corpus input e6f7b9744a7d79b2aa4f7c477707bdd3483f40fa triggers the UBSan
report, but we didn't previously realize this because UBSan has been
disabled in the CI run. We rename the input to indicate its usefulness
as a permanent regression test.
Otherwise, if pull_all fails, we attempt to create a script from NULL,
causing a UBSan report:
bitcoin/script.c:29:28: runtime error: null pointer passed as argument 2, which is declared to never be null
Corpus input bf703c2c20c0818af70a8c4caad6e6fd8cfd1ac6 triggers the UBSan
report, but we didn't previously realize this because UBSan has been
disabled in the CI run. We rename the input to indicate its usefulness
as a permanent regression test.
These corpora were generated with default libFuzzer flags with 30+ hours
of CPU time, and then minimized with:
./fuzz-TARGET -merge=1 -shuffle=0 -prefer_small=1 -use_value_profile=1 corpora/fuzz-TARGET UNMINIMIZED_CORPUS
