Free pending_query_count slot when DNS proof build fails#4591
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TheBlueMatt merged 1 commit intoMay 5, 2026
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`OMDomainResolver` rate-limits in-flight DNSSEC proof builds via a `pending_query_count` counter capped at `MAX_PENDING_RESPONSES` (1024). The counter was only released when the proof build succeeded, so any failure mode -- NXDOMAIN, insecure zones, unreachable resolvers, I/O timeouts, malformed names -- permanently consumed a slot. Because the queried name is attacker-controlled (it travels in over a `DNSSECQuery` onion message from any LN peer, given DNS resolution is an opt-in network-advertised feature), an adversary could exhaust the counter with ~1025 failing queries and persistently DoS the resolver for any subsequent legitimate BIP-353 lookups, until the process is restarted. Always release the slot once the proof build completes, regardless of outcome, and add a regression test which points the resolver at a TCP-refusing local port and asserts the counter returns to zero. Co-Authored-By: HAL 9000
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The fix is correct and the PR looks clean. The core change correctly moves the No issues found. |
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #4591 +/- ##
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- Coverage 86.84% 86.25% -0.59%
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Files 161 159 -2
Lines 109260 109242 -18
Branches 109260 109242 -18
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- Hits 94882 94226 -656
- Misses 11797 12405 +608
- Partials 2581 2611 +30
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Backported to 0.1 in #4680. |
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Backported to 0.2 in #4683. |
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Jun 19, 2026
v0.1.10 - Jun 18, 2026 - "Loupe de Loupe" API Updates =========== * `DefaultMessageRouter` will now always generate blinded message paths that provide no privacy (where our node is the introduction node) for nodes with public channels. This works around an issue which will appear for any nodes with LND peers that enable onion messaging - such peers will refuse to forward BOLT 12 messages from unknown third parties, which most BOLT 12 payers rely on today (#4647). * Explicit `amount_msats` of 0 is rejected in BOLT 12 `Offer`s; `OfferBuilder` now maps 0-amounts to an amount of `None` (#4324). Bug Fixes ========= * Async `ChannelMonitorUpdate` persistence operations which complete, but are not marked as complete in a persisted `ChannelManager` prior to restart, followed immediately by a block connection and then another restart could result in some channel operations hanging leading for force-closures (#4377). * If an MPP payment is claimed but `ChannelMonitorUpdate`s for some parts are still being completed asynchronously, further channel updates (e.g. forwarding another payment) are pending and the node restarts, the channel could have become stuck (#4520). * The presence of unconfirmed transactions actually no longer causes `ElectrumSyncClient` to spuriously fail to sync (#4590). * `FilesystemStore::list_all_keys` will no longer fail if there are stale intermediate files lying around from a previous unclean shutdown (#4618). * When forwarding an HTLC while in a blinded path with proportional fees over 200%, LDK will no longer spuriously allow a forward that pays us 1 msat too little in fees (#4697). * Fixed a rare case where a channel could get stuck on reconnect when using both async `ChannelMonitorUpdate` persistence and async signing (#4684). * `Event::PaymentSent::fee_paid_msat` is no longer `None` in cases where `ChannelManager::abandon_payment` was called before the payment ultimately completes anyway (#4651). * Syncing a `ChainMonitor` using the `Confirm` trait will no longer write some full `ChannelMonitor`s to disk several times per block (#4544). * `OMDomainResolver` now correctly accounts for failed queries when rate limiting, ensuring we continue to respond to queries after failures (#4591). * Calling `ChannelManager::send_payment_with_route` without a `route_params` and with an invalid `Route` will no longer panic (#4707). * `lightning-custom-message`'s handling of `peer_connected` events now ensures that sub-handlers will see a `peer_disconnected` event if a different sub-handler refused the connection by `Err`ing `peer_connected` (#4595). * Incomplete MPP keysend payments will no longer see their HTLCs held until expiry (#4558). * `InvoiceRequestBuilder` will no longer accept a `quantity` of `0` for a BOLT 12 `Offer`, allowing any quantity up to a bound (#4667). * `lightning-custom-message` handlers that return `Ok(None)` when asked to deserialize a message in their defined range no longer cause panics (#4709). * Several spurious debug assertions were fixed (#4537, #4618). Security ======== 0.1.10 fixes a sanitization issue and several denial-of-service vulnerabilities. * `Bolt11Invoice::recover_payee_pub_key` no longer panics if called on an invoice which set an explicit public key, rather than relying on public key recovery. This method is called from `payment_parameters_from_invoice` and `payment_parameters_from_variable_amount_invoice` (#4717). * Maliciously-crafted unpayable invoices which have overflowing feerates will no longer cause an `unwrap` failure panic (#4716). * `possiblyrandom` did not properly generate random data except when it was explicitly configured to. By default this means LDK is vulnerable to various HashDoS attacks (#4719). * `OMNameResolver` will no longer panic when looking up payment instructions which include unicode characters at the start of a TXT record (#4718). * `PrintableString` did not properly sanitize unicode format characters, allowing an attacker to corrupt the rendering of logs or UI (#4593, #4605). * RGS data is now limited in how large of a graph it is able to cause a client to store in memory. Note that RGS data is still considered a DoS vector in general and you should only use semi-trusted RGS data (#4713). * Counterparty-provided strings in failure messages are no longer logged in full, reducing the ability of such a counterparty to spam our logs (#4714). * Reading a corrupted `ChannelManager` or `ProbabilisticScorer` can no longer cause us to allocate large amounts of memory (#4712). Thanks to Project Loupe for reporting most of the issues fixed in this release.
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OMDomainResolverrate-limits in-flight DNSSEC proof builds via apending_query_countcounter capped atMAX_PENDING_RESPONSES(1024). The counter was only released when the proof build succeeded, so any failure mode -- NXDOMAIN, insecure zones, unreachable resolvers, I/O timeouts, malformed names -- permanently consumed a slot.Because the queried name is attacker-controlled (it travels in over a
DNSSECQueryonion message from any LN peer, given DNS resolution is an opt-in network-advertised feature), an adversary could exhaust the counter with ~1025 failing queries and persistently DoS the resolver for any subsequent legitimate BIP-353 lookups, until the process is restarted.Always release the slot once the proof build completes, regardless of outcome, and add a regression test which points the resolver at a TCP-refusing local port and asserts the counter returns to zero.
Co-Authored-By: HAL 9000