feat(fuzz): Adds net class fuzzer

2025-01-31 05:52:55 +08:00 · 2022-11-16 02:24:59 +00:00 · 2022-11-16 02:24:59 +00:00 · 6492f4a18d
commit 6492f4a18d
parent 9cc93e6d41
14 changed files with 824 additions and 31 deletions
--- a/.github/workflows/build_fuzzers.yml
+++ b/.github/workflows/build_fuzzers.yml
@ -19,6 +19,7 @@ jobs:
        fuzz_harness:
        - "device/cdc"
        - "device/msc"
+        - "device/net"

    steps:
    - name: Setup Python
@ -28,6 +29,9 @@ jobs:
      uses: actions/checkout@v3

    - name: Fetch deps
-      run: sudo apt update && sudo apt install libc++abi-dev libc++-dev
+      run: | 
+       sudo apt update && sudo apt install libc++abi-dev libc++-dev
+       make CC=clang CXX=clang++ -C fuzz/${{ matrix.fuzz_harness }} get-deps
+
    - name: Build Fuzzer
      run: make CC=clang CXX=clang++ -C fuzz/${{ matrix.fuzz_harness }}
--- a/fuzz/dcd_fuzz.cc
+++ b/fuzz/dcd_fuzz.cc
@ -172,7 +172,13 @@ bool dcd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t *buffer,
    std::copy(temp.begin(), temp.end(), buffer);
  }
  // Ignore output data as it's not useful for fuzzing without a more
-  // complex fuzzed backend.
+  // complex fuzzed backend. But we need to make sure it's not
+  // optimised out.
+  volatile uint8_t *dont_optimise0 = buffer;
+  volatile uint16_t dont_optimise1 = total_bytes;
+  UNUSED(dont_optimise0);
+  UNUSED(dont_optimise1);
+

  return _fuzz_data_provider->ConsumeBool();
 }
--- a/fuzz/device/cdc/src/fuzz.cc
+++ b/fuzz/device/cdc/src/fuzz.cc
@ -142,33 +142,33 @@ void cdc_task(FuzzedDataProvider *provider) {

    // TODO: Fuzz interface number
    (void)tud_cdc_n_write(0, buffer.data(), buffer.size());
-    break;
-  }
-  case kCdcNWriteChar:
-    // TODO: Fuzz interface number
-    (void)tud_cdc_n_write_char(0, provider->ConsumeIntegral<char>());
-    break;
-  case kCdcNWriteStr: {
-    std::string str = provider->ConsumeRandomLengthString(kMaxBufferSize);
-    // TODO: Fuzz interface number
-    (void)tud_cdc_n_write_str(0, str.c_str());
-    break;
-  }
-  case kCdcNWriteFlush:
-    // TODO: Fuzz interface number
-    (void)tud_cdc_n_write_flush(0);
-    break;
-  case kCdcNWriteAvailable:
-    // TODO: Fuzz interface number
-    (void)tud_cdc_n_write_available(0);
-    break;
-  case kCdcNWriteClear:
-    // TODO: Fuzz interface number
-    (void)tud_cdc_n_write_clear(0);
-    break;
-  case kMaxValue:
-    // Noop.
-    break;
-  }
+  } break;
+  
+case kCdcNWriteChar:
+  // TODO: Fuzz interface number
+  (void)tud_cdc_n_write_char(0, provider->ConsumeIntegral<char>());
+  break;
+case kCdcNWriteStr: {
+  std::string str = provider->ConsumeRandomLengthString(kMaxBufferSize);
+  // TODO: Fuzz interface number
+  (void)tud_cdc_n_write_str(0, str.c_str());
+  break;
+}
+case kCdcNWriteFlush:
+  // TODO: Fuzz interface number
+  (void)tud_cdc_n_write_flush(0);
+  break;
+case kCdcNWriteAvailable:
+  // TODO: Fuzz interface number
+  (void)tud_cdc_n_write_available(0);
+  break;
+case kCdcNWriteClear:
+  // TODO: Fuzz interface number
+  (void)tud_cdc_n_write_clear(0);
+  break;
+case kMaxValue:
+  // Noop.
+  break;
+}
 }
 }
--- a/fuzz/device/net/CMakeLists.txt
+++ b/fuzz/device/net/CMakeLists.txt
@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.5)
+
+include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
+
+# gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
+family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
+
+project(${PROJECT})
+
+# Checks this example is valid for the family and initializes the project
+family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+
+add_executable(${PROJECT})
+
+# Example source
+target_sources(${PROJECT} PUBLIC
+        ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+        ${CMAKE_CURRENT_SOURCE_DIR}/src/msc_disk.c
+        ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+        )
+
+# Example include
+target_include_directories(${PROJECT} PUBLIC
+        ${CMAKE_CURRENT_SOURCE_DIR}/src
+        )
+
+# Configure compilation flags and libraries for the example... see the corresponding function
+# in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${PROJECT})
--- a/fuzz/device/net/Makefile
+++ b/fuzz/device/net/Makefile
@ -0,0 +1,71 @@
+DEPS_SUBMODULES += lib/lwip
+
+include ../../../tools/top.mk
+include ../../make.mk
+
+# suppress warning caused by lwip
+CFLAGS += \
+  -Wno-error=null-dereference \
+  -Wno-error=unused-parameter \
+  -Wno-error=unused-variable
+
+INC += \
+  src \
+  $(TOP)/hw \
+  $(TOP)/lib/lwip/src/include \
+  $(TOP)/lib/lwip/src/include/ipv4 \
+  $(TOP)/lib/lwip/src/include/lwip/apps \
+  $(TOP)/lib/networking
+
+# Example source
+SRC_C += $(addprefix $(CURRENT_PATH)/, $(wildcard src/*.c))
+SRC_CXX += $(addprefix $(CURRENT_PATH)/, $(wildcard src/*.cc))
+
+# lwip sources
+SRC_C += \
+  lib/lwip/src/core/altcp.c \
+  lib/lwip/src/core/altcp_alloc.c \
+  lib/lwip/src/core/altcp_tcp.c \
+  lib/lwip/src/core/def.c \
+  lib/lwip/src/core/dns.c \
+  lib/lwip/src/core/inet_chksum.c \
+  lib/lwip/src/core/init.c \
+  lib/lwip/src/core/ip.c \
+  lib/lwip/src/core/mem.c \
+  lib/lwip/src/core/memp.c \
+  lib/lwip/src/core/netif.c \
+  lib/lwip/src/core/pbuf.c \
+  lib/lwip/src/core/raw.c \
+  lib/lwip/src/core/stats.c \
+  lib/lwip/src/core/sys.c \
+  lib/lwip/src/core/tcp.c \
+  lib/lwip/src/core/tcp_in.c \
+  lib/lwip/src/core/tcp_out.c \
+  lib/lwip/src/core/timeouts.c \
+  lib/lwip/src/core/udp.c \
+  lib/lwip/src/core/ipv4/autoip.c \
+  lib/lwip/src/core/ipv4/dhcp.c \
+  lib/lwip/src/core/ipv4/etharp.c \
+  lib/lwip/src/core/ipv4/icmp.c \
+  lib/lwip/src/core/ipv4/igmp.c \
+  lib/lwip/src/core/ipv4/ip4.c \
+  lib/lwip/src/core/ipv4/ip4_addr.c \
+  lib/lwip/src/core/ipv4/ip4_frag.c \
+  lib/lwip/src/core/ipv6/dhcp6.c \
+  lib/lwip/src/core/ipv6/ethip6.c \
+  lib/lwip/src/core/ipv6/icmp6.c \
+  lib/lwip/src/core/ipv6/inet6.c \
+  lib/lwip/src/core/ipv6/ip6.c \
+  lib/lwip/src/core/ipv6/ip6_addr.c \
+  lib/lwip/src/core/ipv6/ip6_frag.c \
+  lib/lwip/src/core/ipv6/mld6.c \
+  lib/lwip/src/core/ipv6/nd6.c \
+  lib/lwip/src/netif/ethernet.c \
+  lib/lwip/src/netif/slipif.c \
+  lib/lwip/src/apps/http/httpd.c \
+  lib/lwip/src/apps/http/fs.c \
+  lib/networking/dhserver.c \
+  lib/networking/dnserver.c \
+  lib/networking/rndis_reports.c
+
+include ../../rules.mk
--- a/fuzz/device/net/skip.txt
+++ b/fuzz/device/net/skip.txt
@ -0,0 +1 @@
+mcu:SAMD11
--- a/fuzz/device/net/src/arch/cc.h
+++ b/fuzz/device/net/src/arch/cc.h
@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
+ * All rights reserved. 
+ * 
+ * Redistribution and use in source and binary forms, with or without modification, 
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ * 
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+#ifndef __CC_H__
+#define __CC_H__
+
+//#include "cpu.h"
+
+typedef int sys_prot_t;
+
+
+
+/* define compiler specific symbols */
+#if defined (__ICCARM__)
+
+#define PACK_STRUCT_BEGIN
+#define PACK_STRUCT_STRUCT 
+#define PACK_STRUCT_END
+#define PACK_STRUCT_FIELD(x) x
+#define PACK_STRUCT_USE_INCLUDES
+
+#elif defined (__CC_ARM)
+
+#define PACK_STRUCT_BEGIN __packed
+#define PACK_STRUCT_STRUCT 
+#define PACK_STRUCT_END
+#define PACK_STRUCT_FIELD(x) x
+
+#elif defined (__GNUC__)
+
+#define PACK_STRUCT_BEGIN
+#define PACK_STRUCT_STRUCT __attribute__ ((__packed__))
+#define PACK_STRUCT_END
+#define PACK_STRUCT_FIELD(x) x
+
+#elif defined (__TASKING__)
+
+#define PACK_STRUCT_BEGIN
+#define PACK_STRUCT_STRUCT
+#define PACK_STRUCT_END
+#define PACK_STRUCT_FIELD(x) x
+
+#endif
+
+#define LWIP_PLATFORM_ASSERT(x) do { if(!(x)) while(1); } while(0)
+
+#endif /* __CC_H__ */
--- a/fuzz/device/net/src/fuzz.cc
+++ b/fuzz/device/net/src/fuzz.cc
@ -0,0 +1,99 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Nathaniel Brough
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include <cassert>
+#include <fuzzer/FuzzedDataProvider.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "class/cdc/cdc_device.h"
+#include "class/net/net_device.h"
+#include "fuzz/fuzz.h"
+#include "tusb.h"
+#include <cstdint>
+#include <string>
+#include <vector>
+
+extern "C" {
+
+#define FUZZ_ITERATIONS 500
+
+//--------------------------------------------------------------------+
+// MACRO CONSTANT TYPEDEF PROTYPES
+//--------------------------------------------------------------------+
+
+void net_task(FuzzedDataProvider *provider);
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  FuzzedDataProvider provider(Data, Size);
+  std::vector<uint8_t> callback_data = provider.ConsumeBytes<uint8_t>(
+      provider.ConsumeIntegralInRange<size_t>(0, Size));
+  fuzz_init(callback_data.data(), callback_data.size());
+  // init device stack on configured roothub port
+  tud_init(BOARD_TUD_RHPORT);
+
+  for (int i = 0; i < FUZZ_ITERATIONS; i++) {
+    if (provider.remaining_bytes() == 0) {
+      return 0;
+    }
+    tud_int_handler(provider.ConsumeIntegral<uint8_t>());
+    tud_task(); // tinyusb device task
+    net_task(&provider);
+  }
+
+  return 0;
+}
+
+//--------------------------------------------------------------------+
+// USB CDC
+//--------------------------------------------------------------------+
+enum NetApiFuncs {
+  kNetworkRecvRenew,
+  kNetworkCanXmit,
+  kNetworkXmit,
+  kMaxValue,
+};
+
+void net_task(FuzzedDataProvider *provider) {
+
+  assert(provider != NULL);
+  switch (provider->ConsumeEnum<NetApiFuncs>()) {
+  
+  case kNetworkRecvRenew:
+    tud_network_recv_renew();
+    break;
+  case kNetworkCanXmit:
+ (void)tud_network_can_xmit(provider->ConsumeIntegral<uint16_t>());
+  case kNetworkXmit:
+    // TODO: Actuall pass real values here later.
+    tud_network_xmit(NULL, 0);
+
+  case kMaxValue:
+    // Noop.
+    break;
+  }
+}
+}
--- a/fuzz/device/net/src/lwipopts.h
+++ b/fuzz/device/net/src/lwipopts.h
@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
+ * All rights reserved. 
+ * 
+ * Redistribution and use in source and binary forms, with or without modification, 
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ * 
+ * Author: Simon Goldschmidt
+ *
+ */
+#ifndef __LWIPOPTS_H__
+#define __LWIPOPTS_H__
+
+/* Prevent having to link sys_arch.c (we don't test the API layers in unit tests) */
+#define NO_SYS                          1
+#define MEM_ALIGNMENT                   4
+#define LWIP_RAW                        0
+#define LWIP_NETCONN                    0
+#define LWIP_SOCKET                     0
+#define LWIP_DHCP                       0
+#define LWIP_ICMP                       1
+#define LWIP_UDP                        1
+#define LWIP_TCP                        1
+#define LWIP_IPV4                       1
+#define LWIP_IPV6                       0
+#define ETH_PAD_SIZE                    0
+#define LWIP_IP_ACCEPT_UDP_PORT(p)      ((p) == PP_NTOHS(67))
+
+#define TCP_MSS                         (1500 /*mtu*/ - 20 /*iphdr*/ - 20 /*tcphhr*/)
+#define TCP_SND_BUF                     (2 * TCP_MSS)
+#define TCP_WND                         (TCP_MSS)
+
+#define ETHARP_SUPPORT_STATIC_ENTRIES   1
+
+#define LWIP_HTTPD_CGI                  0
+#define LWIP_HTTPD_SSI                  0
+#define LWIP_HTTPD_SSI_INCLUDE_TAG      0
+
+#define LWIP_SINGLE_NETIF               1
+
+#define PBUF_POOL_SIZE                  2
+
+#define HTTPD_USE_CUSTOM_FSDATA         0
+
+#define LWIP_MULTICAST_PING             1
+#define LWIP_BROADCAST_PING             1
+#define LWIP_IPV6_MLD                   0
+#define LWIP_IPV6_SEND_ROUTER_SOLICIT   0
+
+#endif /* __LWIPOPTS_H__ */
--- a/fuzz/device/net/src/tusb_config.h
+++ b/fuzz/device/net/src/tusb_config.h
@ -0,0 +1,122 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Nathaniel Brough
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef _TUSB_CONFIG_H_
+#define _TUSB_CONFIG_H_
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+//--------------------------------------------------------------------+
+// Board Specific Configuration
+//--------------------------------------------------------------------+
+
+// RHPort number used for device can be defined by board.mk, default to port 0
+#ifndef BOARD_TUD_RHPORT
+#define BOARD_TUD_RHPORT      0
+#endif
+
+// RHPort max operational speed can defined by board.mk
+#ifndef BOARD_TUD_MAX_SPEED
+#define BOARD_TUD_MAX_SPEED   OPT_MODE_DEFAULT_SPEED
+#endif
+
+//--------------------------------------------------------------------
+// Common Configuration
+//--------------------------------------------------------------------
+
+// defined by compiler flags for flexibility
+#ifndef CFG_TUSB_MCU
+#error CFG_TUSB_MCU must be defined
+#endif
+
+#ifndef CFG_TUSB_OS
+#define CFG_TUSB_OS           OPT_OS_NONE
+#endif
+
+#ifndef CFG_TUSB_DEBUG
+#define CFG_TUSB_DEBUG        0
+#endif
+
+// Enable Device stack
+#define CFG_TUD_ENABLED       1
+
+// Default is max speed that hardware controller could support with on-chip PHY
+#define CFG_TUD_MAX_SPEED     BOARD_TUD_MAX_SPEED
+
+/* USB DMA on some MCUs can only access a specific SRAM region with restriction on alignment.
+ * Tinyusb use follows macros to declare transferring memory so that they can be put
+ * into those specific section.
+ * e.g
+ * - CFG_TUSB_MEM SECTION : __attribute__ (( section(".usb_ram") ))
+ * - CFG_TUSB_MEM_ALIGN   : __attribute__ ((aligned(4)))
+ */
+#ifndef CFG_TUSB_MEM_SECTION
+#define CFG_TUSB_MEM_SECTION
+#endif
+
+#ifndef CFG_TUSB_MEM_ALIGN
+#define CFG_TUSB_MEM_ALIGN    __attribute__ ((aligned(4)))
+#endif
+
+//--------------------------------------------------------------------
+// DEVICE CONFIGURATION
+//--------------------------------------------------------------------
+
+#ifndef CFG_TUD_ENDPOINT0_SIZE
+#define CFG_TUD_ENDPOINT0_SIZE    64
+#endif
+
+//------------- CLASS -------------//
+#define CFG_TUD_CDC              1
+#define CFG_TUD_MSC              0
+#define CFG_TUD_HID              0
+#define CFG_TUD_MIDI             0
+#define CFG_TUD_VENDOR           0
+
+// Network class has 2 drivers: ECM/RNDIS and NCM.
+// Only one of the drivers can be enabled
+#define CFG_TUD_ECM_RNDIS     1
+#define CFG_TUD_NCM           (1-CFG_TUD_ECM_RNDIS)
+
+// CDC FIFO size of TX and RX
+#define CFG_TUD_CDC_RX_BUFSIZE   (TUD_OPT_HIGH_SPEED ? 512 : 64)
+#define CFG_TUD_CDC_TX_BUFSIZE   (TUD_OPT_HIGH_SPEED ? 512 : 64)
+
+// CDC Endpoint transfer buffer size, more is faster
+#define CFG_TUD_CDC_EP_BUFSIZE   (TUD_OPT_HIGH_SPEED ? 512 : 64)
+
+// MSC Buffer size of Device Mass storage
+#define CFG_TUD_MSC_EP_BUFSIZE   512
+
+
+
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* _TUSB_CONFIG_H_ */
--- a/fuzz/device/net/src/usb_descriptors.cc
+++ b/fuzz/device/net/src/usb_descriptors.cc
@ -0,0 +1,229 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "tusb.h"
+
+/* A combination of interfaces must have a unique product id, since PC will save
+ * device driver after the first plug.
+ * Auto ProductID layout's Bitmap:
+ *   [MSB]         HID | CDC          [LSB]
+ */
+#define _PID_MAP(itf, n) ((CFG_TUD_##itf) << (n))
+#define USB_PID                                                                \
+  (0x4000 | _PID_MAP(CDC, 0) | _PID_MAP(HID, 2) | _PID_MAP(MIDI, 3) |          \
+   _PID_MAP(VENDOR, 4))
+
+#define USB_VID 0xCafe
+#define USB_BCD 0x0200
+
+//--------------------------------------------------------------------+
+// Device Descriptors
+//--------------------------------------------------------------------+
+
+// Invoked when received GET DEVICE DESCRIPTOR
+// Application return pointer to descriptor
+uint8_t const *tud_descriptor_device_cb(void) {
+  static tusb_desc_device_t const desc_device = {
+      .bLength = sizeof(tusb_desc_device_t),
+      .bDescriptorType = TUSB_DESC_DEVICE,
+      .bcdUSB = USB_BCD,
+
+      // Use Interface Association Descriptor (IAD) for CDC
+      // As required by USB Specs IAD's subclass must be common class (2) and
+      // protocol must be IAD (1)
+      .bDeviceClass = TUSB_CLASS_MISC,
+      .bDeviceSubClass = MISC_SUBCLASS_COMMON,
+      .bDeviceProtocol = MISC_PROTOCOL_IAD,
+
+      .bMaxPacketSize0 = CFG_TUD_ENDPOINT0_SIZE,
+
+      .idVendor = USB_VID,
+      .idProduct = USB_PID,
+      .bcdDevice = 0x0100,
+
+      .iManufacturer = 0x01,
+      .iProduct = 0x02,
+      .iSerialNumber = 0x03,
+
+      .bNumConfigurations = 0x01};
+
+  return (uint8_t const *)&desc_device;
+}
+
+//--------------------------------------------------------------------+
+// Configuration Descriptor
+//--------------------------------------------------------------------+
+
+enum { ITF_NUM_CDC = 0, ITF_NUM_CDC_DATA, ITF_NUM_TOTAL };
+
+#define EPNUM_CDC_NOTIF 0x81
+#define EPNUM_CDC_OUT 0x02
+#define EPNUM_CDC_IN 0x82
+
+#define CONFIG_TOTAL_LEN (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN)
+
+// full speed configuration
+uint8_t const desc_fs_configuration[] = {
+    // Config number, interface count, string index, total length, attribute,
+    // power in mA
+    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
+
+    // Interface number, string index, EP notification address and size, EP data
+    // address (out, in) and size.
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT,
+                       EPNUM_CDC_IN, 64),
+};
+
+#if TUD_OPT_HIGH_SPEED
+// Per USB specs: high speed capable device must report device_qualifier and
+// other_speed_configuration
+
+// high speed configuration
+uint8_t const desc_hs_configuration[] = {
+    // Config number, interface count, string index, total length, attribute,
+    // power in mA
+    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
+
+    // Interface number, string index, EP notification address and size, EP data
+    // address (out, in) and size.
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT,
+                       EPNUM_CDC_IN, 512),
+};
+
+// other speed configuration
+uint8_t desc_other_speed_config[CONFIG_TOTAL_LEN];
+
+// device qualifier is mostly similar to device descriptor since we don't change
+// configuration based on speed
+tusb_desc_device_qualifier_t const desc_device_qualifier = {
+    .bLength = sizeof(tusb_desc_device_qualifier_t),
+    .bDescriptorType = TUSB_DESC_DEVICE_QUALIFIER,
+    .bcdUSB = USB_BCD,
+
+    .bDeviceClass = TUSB_CLASS_MISC,
+    .bDeviceSubClass = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol = MISC_PROTOCOL_IAD,
+
+    .bMaxPacketSize0 = CFG_TUD_ENDPOINT0_SIZE,
+    .bNumConfigurations = 0x01,
+    .bReserved = 0x00};
+
+// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long
+// enough for transfer to complete. device_qualifier descriptor describes
+// information about a high-speed capable device that would change if the device
+// were operating at the other speed. If not highspeed capable stall this
+// request.
+uint8_t const *tud_descriptor_device_qualifier_cb(void) {
+  return (uint8_t const *)&desc_device_qualifier;
+}
+
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long
+// enough for transfer to complete Configuration descriptor in the other speed
+// e.g if high speed then this is for full speed and vice versa
+uint8_t const *tud_descriptor_other_speed_configuration_cb(uint8_t index) {
+  (void)index; // for multiple configurations
+
+  // if link speed is high return fullspeed config, and vice versa
+  // Note: the descriptor type is OHER_SPEED_CONFIG instead of CONFIG
+  memcpy(desc_other_speed_config,
+         (tud_speed_get() == TUSB_SPEED_HIGH) ? desc_fs_configuration
+                                              : desc_hs_configuration,
+         CONFIG_TOTAL_LEN);
+
+  desc_other_speed_config[1] = TUSB_DESC_OTHER_SPEED_CONFIG;
+
+  return desc_other_speed_config;
+}
+
+#endif // highspeed
+
+// Invoked when received GET CONFIGURATION DESCRIPTOR
+// Application return pointer to descriptor
+// Descriptor contents must exist long enough for transfer to complete
+uint8_t const *tud_descriptor_configuration_cb(uint8_t index) {
+  (void)index; // for multiple configurations
+
+#if TUD_OPT_HIGH_SPEED
+  // Although we are highspeed, host may be fullspeed.
+  return (tud_speed_get() == TUSB_SPEED_HIGH) ? desc_hs_configuration
+                                              : desc_fs_configuration;
+#else
+  return desc_fs_configuration;
+#endif
+}
+
+//--------------------------------------------------------------------+
+// String Descriptors
+//--------------------------------------------------------------------+
+
+// array of pointer to string descriptors
+char const *string_desc_arr[] = {
+    (const char[]){0x09, 0x04}, // 0: is supported language is English (0x0409)
+    "TinyUSB",                  // 1: Manufacturer
+    "TinyUSB Device",           // 2: Product
+    "123456789012",             // 3: Serials, should use chip ID
+    "TinyUSB CDC",              // 4: CDC Interface
+};
+
+static uint16_t _desc_str[32];
+
+// Invoked when received GET STRING DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long
+// enough for transfer to complete
+uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
+  (void)langid;
+
+  uint8_t chr_count;
+
+  if (index == 0) {
+    memcpy(&_desc_str[1], string_desc_arr[0], 2);
+    chr_count = 1;
+  } else {
+    // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+    // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+
+    if (!(index < sizeof(string_desc_arr) / sizeof(string_desc_arr[0])))
+      return NULL;
+
+    const char *str = string_desc_arr[index];
+
+    // Cap at max char
+    chr_count = (uint8_t)strlen(str);
+    if (chr_count > 31)
+      chr_count = 31;
+
+    // Convert ASCII string into UTF-16
+    for (uint8_t i = 0; i < chr_count; i++) {
+      _desc_str[1 + i] = str[i];
+    }
+  }
+
+  // first byte is length (including header), second byte is string type
+  _desc_str[0] = (uint16_t)((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
+
+  return _desc_str;
+}
--- a/fuzz/make.mk
+++ b/fuzz/make.mk
@ -43,6 +43,8 @@ INC   += $(TOP)/$(FAMILY_PATH)
 CFLAGS += \
  -ggdb \
  -fsanitize=fuzzer \
+  -fsanitize=address \
+  -fsanitize=undefined \
  -fdata-sections \
  -ffunction-sections \
  -fno-strict-aliasing \
@ -66,7 +68,8 @@ CFLAGS += \
  -Wnull-dereference \
  -Wuninitialized \
  -Wunused \
-  -Wredundant-decls
+  -Wredundant-decls \
+  -O1

 CFLAGS += \
  -DOPT_MCU_FUZZ=1 \
--- a/fuzz/net_fuzz.cc
+++ b/fuzz/net_fuzz.cc
@ -0,0 +1,82 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Nathaniel Brough
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "tusb_config.h"
+#if defined(CFG_TUD_ECM_RNDIS) || defined(CFG_TUD_NCM)
+
+#include "class/net/net_device.h"
+#include "fuzz_private.h"
+#include <cassert>
+#include <cstdint>
+#include <vector>
+#include "lwip/sys.h"
+
+extern "C" {
+bool tud_network_recv_cb(const uint8_t *src, uint16_t size) {
+  assert(_fuzz_data_provider.has_value());
+  (void)src;
+  (void)size;
+  return _fuzz_data_provider->ConsumeBool();
+}
+
+// client must provide this: copy from network stack packet pointer to dst
+uint16_t tud_network_xmit_cb(uint8_t *dst, void *ref, uint16_t arg) {
+  (void)ref;
+  (void)arg;
+
+  assert(_fuzz_data_provider.has_value());
+
+  uint16_t size = _fuzz_data_provider->ConsumeIntegral<uint16_t>();
+  std::vector<uint8_t> temp = _fuzz_data_provider->ConsumeBytes<uint8_t>(size);
+  memcpy(dst, temp.data(), temp.size());
+  return size;
+}
+
+/* lwip has provision for using a mutex, when applicable */
+sys_prot_t sys_arch_protect(void) { return 0; }
+void sys_arch_unprotect(sys_prot_t pval) { (void)pval; }
+
+//------------- ECM/RNDIS -------------//
+
+// client must provide this: initialize any network state back to the beginning
+void tud_network_init_cb(void) {
+  // NoOp.
+}
+
+// client must provide this: 48-bit MAC address
+// TODO removed later since it is not part of tinyusb stack
+const uint8_t tud_network_mac_address[6] = {0};
+
+//------------- NCM -------------//
+
+// callback to client providing optional indication of internal state of network
+// driver
+void tud_network_link_state_cb(bool state) {
+  (void)state;
+  // NoOp.
+}
+}
+
+#endif
--- a/fuzz/rules.mk
+++ b/fuzz/rules.mk
@ -43,6 +43,7 @@ SRC_CXX += \
 	fuzz/dcd_fuzz.cc \
 	fuzz/fuzz.cc \
 	fuzz/msc_fuzz.cc \
+	fuzz/net_fuzz.cc \
 	fuzz/usbd_fuzz.cc

 # TinyUSB stack include