quic: reject zero addressLRUSize

SocketAddressLRU::Upsert always inserts an entry before evicting down
to max_size_. With max_size_ == 0, it evicts the entry it just
inserted and then accesses the now-missing key via
map_[address]->second. operator[] recreates the key with a
default-constructed std::list iterator, which is then dereferenced.
This is undefined behavior, observed as a SIGSEGV in Endpoint::Receive
on the first UDP packet accepted by a QuicEndpoint constructed with
{ addressLRUSize: 0 }.

SocketAddressLRU has no useful semantics for a zero-capacity cache,
and Upsert's callers rely on it returning a valid pointer. Reject 0
(and 0n) at the options-parsing boundary instead of changing Upsert's
contract.

Signed-off-by: Christian Aurich <christian.aurichzm@gmail.com>
PR-URL: #65827
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tim Perry <pimterry@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

Author: christianaurichzm

doc/api/quic.md

@@ -2657,8 +2657,8 @@ added: v23.8.0
 
 The endpoint maintains an internal cache of validated socket addresses as a
 performance optimization. This option sets the maximum number of addresses
-that are cached. This is an advanced option that users typically won't have
-need to specify.
+that are cached. The value must be greater than `0`. This is an advanced option
+that users typically won't have need to specify.
 
 #### `endpointOptions.disableStatelessReset`
 

src/quic/endpoint.cc

@@ -248,6 +248,17 @@ Maybe<Endpoint::Options> Endpoint::Options::From(Environment* env,
     return Nothing<Options>();
   }
 
+  // SocketAddressLRU::Upsert requires a positive capacity. With max_size_ ==
+  // 0, the newly inserted entry is immediately evicted, and the final
+  // map_[address] creates a default list iterator that is then
+  // dereferenced, causing UB (observed as a SIGSEGV in Endpoint::Receive on
+  // the first accepted connection).
+  if (options.address_lru_size == 0) {
+    THROW_ERR_INVALID_ARG_VALUE(
+        env, "The addressLRUSize option must be greater than 0");
+    return Nothing<Options>();
+  }
+
   Local<Value> address;
   if (!params->Get(env->context(), env->address_string()).ToLocal(&address)) {
     return Nothing<Options>();

test/parallel/test-quic-internal-endpoint-options.mjs

@@ -56,7 +56,7 @@ const cases = [
     valid: [
       1, 10, 100, 1000, 10000, 10000n,
     ],
-    invalid: [-1, -1n, 'a', null, false, true, {}, [], () => {}]
+    invalid: [-1, -1n, 0, 0n, 'a', null, false, true, {}, [], () => {}]
   },
   {
     key: 'retryRate',