mac_nr: add error handling when unpacking SCH MAC PDU

* only handle PDU if unpacking was successfull
* add TC unpacking with malformed PDU

lib/include/srsran/mac/mac_sch_pdu_nr.h

@@ -123,7 +123,7 @@ public:
   mac_sch_pdu_nr(bool ulsch_ = false) : ulsch(ulsch_), logger(srslog::fetch_basic_logger("MAC")) {}
 
   void                     pack();
-  void                     unpack(const uint8_t* payload, const uint32_t& len);
+  int                      unpack(const uint8_t* payload, const uint32_t& len);
   uint32_t                 get_num_subpdus();
   const mac_sch_subpdu_nr& get_subpdu(const uint32_t& index);
   bool                     is_ulsch();

lib/src/mac/mac_sch_pdu_nr.cc

@@ -293,14 +293,14 @@ void mac_sch_pdu_nr::pack()
   }
 }
 
-void mac_sch_pdu_nr::unpack(const uint8_t* payload, const uint32_t& len)
+int mac_sch_pdu_nr::unpack(const uint8_t* payload, const uint32_t& len)
 {
   uint32_t offset = 0;
   while (offset < len) {
     mac_sch_subpdu_nr sch_pdu(this);
     if (sch_pdu.read_subheader(payload + offset) == SRSRAN_ERROR) {
-      logger.error("Error parsing NR MAC PDU (len=%d, offset=%d)\n", len, offset);
-      return;
+      logger.error("Malformed MAC PDU (len=%d, offset=%d)\n", len, offset);
+      return SRSRAN_ERROR;
     }
     offset += sch_pdu.get_total_length();
     if (sch_pdu.get_lcid() == mac_sch_subpdu_nr::PADDING) {
@@ -312,8 +312,11 @@ void mac_sch_pdu_nr::unpack(const uint8_t* payload, const uint32_t& len)
     subpdus.push_back(sch_pdu);
   }
   if (offset != len) {
-    logger.error("Error parsing NR MAC PDU (len=%d, offset=%d)\n", len, offset);
+    logger.error("Malformed MAC PDU (len=%d, offset=%d)\n", len, offset);
+    return SRSRAN_ERROR;
   }
+
+  return SRSRAN_SUCCESS;
 }
 
 uint32_t mac_sch_pdu_nr::get_num_subpdus()

lib/test/mac/mac_pdu_nr_test.cc

@@ -624,6 +624,31 @@ int mac_dl_sch_pdu_unpack_and_pack_test6()
   return SRSRAN_SUCCESS;
 }
 
+int mac_ul_sch_pdu_unpack_test6()
+{
+  // Malformed MAC PDU
+  uint8_t tv[] = {0x04, 0xe7, 0x00, 0x80, 0x04, 0x45, 0x00, 0x00, 0xe4, 0x4b, 0x9d, 0x40, 0x00, 0x40, 0x01, 0x69, 0x28,
+                  0xc0, 0xa8, 0x02, 0x02, 0xc0, 0xa8, 0x02, 0x01, 0x08, 0x00, 0x3a, 0xbc, 0x65, 0x4a, 0x00, 0x01, 0x94,
+                  0x85, 0x70, 0x60, 0x00, 0x00, 0x00, 0x00, 0xaa, 0x1b, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x11,
+                  0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22,
+                  0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33,
+                  0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44,
+                  0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55,
+                  0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
+                  0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+                  0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88,
+                  0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97};
+
+  if (pcap_handle) {
+    pcap_handle->write_ul_crnti_nr(tv, sizeof(tv), PCAP_CRNTI, true, PCAP_TTI);
+  }
+
+  srsran::mac_sch_pdu_nr pdu(true);
+  TESTASSERT(pdu.unpack(tv, sizeof(tv)) == SRSRAN_ERROR);
+
+  return SRSRAN_SUCCESS;
+}
+
 int main(int argc, char** argv)
 {
 #if PCAP
@@ -712,6 +737,11 @@ int main(int argc, char** argv)
     return SRSRAN_ERROR;
   }
 
+  if (mac_ul_sch_pdu_unpack_test6()) {
+    fprintf(stderr, "mac_ul_sch_pdu_unpack_test6() failed.\n");
+    return SRSRAN_ERROR;
+  }
+
   if (pcap_handle) {
     pcap_handle->close();
   }

srsenb/src/stack/mac/mac_nr.cc

@@ -230,7 +230,9 @@ int mac_nr::handle_pdu(srsran::unique_byte_buffer_t pdu)
   logger.info(pdu->msg, pdu->N_bytes, "Handling MAC PDU (%d B)", pdu->N_bytes);
 
   ue_rx_pdu.init_rx(true);
-  ue_rx_pdu.unpack(pdu->msg, pdu->N_bytes);
+  if (ue_rx_pdu.unpack(pdu->msg, pdu->N_bytes) != SRSRAN_SUCCESS) {
+    return SRSRAN_ERROR;
+  }
 
   for (uint32_t i = 0; i < ue_rx_pdu.get_num_subpdus(); ++i) {
     srsran::mac_sch_subpdu_nr subpdu = ue_rx_pdu.get_subpdu(i);

srsue/src/stack/mac_nr/mac_nr.cc

@@ -423,7 +423,9 @@ void mac_nr::handle_pdu(srsran::unique_byte_buffer_t pdu)
   logger.info(pdu->msg, pdu->N_bytes, "Handling MAC PDU (%d B)", pdu->N_bytes);
 
   rx_pdu.init_rx();
-  rx_pdu.unpack(pdu->msg, pdu->N_bytes);
+  if (rx_pdu.unpack(pdu->msg, pdu->N_bytes) != SRSRAN_SUCCESS) {
+    return;
+  }
 
   for (uint32_t i = 0; i < rx_pdu.get_num_subpdus(); ++i) {
     srsran::mac_sch_subpdu_nr subpdu = rx_pdu.get_subpdu(i);