1 files changed, 29 insertions, 2 deletions
diff --git a/test/syscalls/linux/udp_socket.cc b/test/syscalls/linux/udp_socket.cc
index 34255bfb8..90ef8bf21 100644
--- a/test/syscalls/linux/udp_socket.cc
+++ b/test/syscalls/linux/udp_socket.cc
@@ -375,8 +375,6 @@ TEST_P(UdpSocketTest, BindInUse) {
 }
 
 TEST_P(UdpSocketTest, ConnectWriteToInvalidPort) {
-  ASSERT_NO_ERRNO(BindLoopback());
-
   // Discover a free unused port by creating a new UDP socket, binding it
   // recording the just bound port and closing it. This is not guaranteed as it
   // can still race with other port UDP sockets trying to bind a port at the
@@ -410,6 +408,35 @@ TEST_P(UdpSocketTest, ConnectWriteToInvalidPort) {
   ASSERT_EQ(optlen, sizeof(err));
 }
 
+TEST_P(UdpSocketTest, ConnectSimultaneousWriteToInvalidPort) {
+  // Discover a free unused port by creating a new UDP socket, binding it
+  // recording the just bound port and closing it. This is not guaranteed as it
+  // can still race with other port UDP sockets trying to bind a port at the
+  // same time.
+  struct sockaddr_storage addr_storage = InetLoopbackAddr();
+  socklen_t addrlen = sizeof(addr_storage);
+  struct sockaddr* addr = reinterpret_cast<struct sockaddr*>(&addr_storage);
+  FileDescriptor s =
+      ASSERT_NO_ERRNO_AND_VALUE(Socket(GetFamily(), SOCK_DGRAM, IPPROTO_UDP));
+  ASSERT_THAT(bind(s.get(), addr, addrlen), SyscallSucceeds());
+  ASSERT_THAT(getsockname(s.get(), addr, &addrlen), SyscallSucceeds());
+  EXPECT_EQ(addrlen, addrlen_);
+  EXPECT_NE(*Port(&addr_storage), 0);
+  ASSERT_THAT(close(s.release()), SyscallSucceeds());
+
+  // Now connect to the port that we just released.
+  ScopedThread t([&] {
+    ASSERT_THAT(connect(sock_.get(), addr, addrlen_), SyscallSucceeds());
+  });
+
+  char buf[512];
+  RandomizeBuffer(buf, sizeof(buf));
+  // Send from sock_ to an unbound port.
+  ASSERT_THAT(sendto(sock_.get(), buf, sizeof(buf), 0, addr, addrlen_),
+              SyscallSucceedsWithValue(sizeof(buf)));
+  t.Join();
+}
+
 TEST_P(UdpSocketTest, ReceiveAfterConnect) {
   ASSERT_NO_ERRNO(BindLoopback());
   ASSERT_THAT(connect(sock_.get(), bind_addr_, addrlen_), SyscallSucceeds());