rpc: render Type::ANY in help text instead of aborting
What the developer wrote
Authored by will
rpc: render Type::ANY in help text instead of aborting
RPCResult::Type::ANY triggers NONFATAL_UNREACHABLE() in ToSections(),
which crashes the help() RPC when a command uses Type::ANY in a
nested result field.
Previously this was never hit because Type::ANY was only used as a
top-level alternate result type, filtered out before ToSections() is
called.
getopenrpcinfo() will use this result type, so render it like other
types allowing it to be used in nested result definitions like schema.
What changed, and why it matters
This is a small bug-fix in Bitcoin Core's RPC help system. A special placeholder result type called Type::ANY previously caused the help() command to crash with an 'unreachable' assertion when it appeared inside a nested result description. The change makes it render as 'xxx' with description 'any' instead, matching how other types are displayed. It is a denial-of-service-style crash only for the help() RPC output, not for transaction processing, consensus, or wallet operations.
Treat as a routine bug fix. No urgent security response is warranted. Reviewers may want to confirm that no other Type::ANY usages remain unhandled and that getopenrpcinfo() help output renders correctly after the change.
Security signals we found
Crash/assertion in RPC help generation (NONFATAL_UNREACHABLE)
Denial-of-service vector limited to help() RPC output
No consensus, networking, or wallet code affected
Fix is a one-line behavior change in a single utility function
Evidence from the diff
In src/rpc/util.cpp, RPCResult::ToSections() previously called NONFATAL_UNREACHABLE() for Type::ANY, causing a non-fatal abort when generating help text for any RPC whose nested result schema included Type::ANY. The patch replaces the unreachable assertion with a normal section push (indent + maybe_key + ‘xxx’ + maybe_separator, Description(‘any’)), consistent with other scalar/placeholder types. The commit message notes this was previously unhit because Type::ANY was only used as a top-level alternate result type filtered out before ToSections(), and that getopenrpcinfo() will use it nested.
Changed components
src/rpc/util.cppRPC help text generationhelp() RPC commandInspect captured patch +2 / −1
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index 410bb741..8c5ee303 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -1032,7 +1032,8 @@ void RPCResult::ToSections(Sections& sections, const OuterType outer_type, const
switch (m_type) {
case Type::ANY: {
- NONFATAL_UNREACHABLE(); // Only for testing
+ sections.PushSection({indent + maybe_key + "xxx" + maybe_separator, Description("any")});
+ return;
}
case Type::NONE: {
sections.PushSection({indent + "null" + maybe_separator, Description("json null")});
Why this scored 22/100
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