lib,rlc_am_nr: fixed stack smashing bug that happened when too many NACKs were present in the status report

lib/include/srsran/rlc/rlc_am_nr_packing.h

@@ -19,7 +19,9 @@
 
 namespace srsran {
 
-const uint32_t INVALID_RLC_SN = 0xFFFFFFFF;
+const uint32_t RLC_AM_NR_WINDOW_SIZE_12BIT = 4096;
+const uint32_t RLC_AM_NR_WINDOW_SIZE_18BIT = 262144;
+const uint32_t INVALID_RLC_SN              = 0xFFFFFFFF;
 
 ///< AM NR PDU header
 struct rlc_am_nr_pdu_header_t {
@@ -82,7 +84,7 @@ typedef struct {
   uint32_t                     ack_sn; ///< SN of the next not received RLC Data PDU
   uint16_t                     N_nack; ///< number of NACKs
   uint8_t           nack_range;        ///< number of consecutively lost RLC SDUs starting from and including NACK_SN
-  rlc_status_nack_t nacks[RLC_AM_WINDOW_SIZE];
+  rlc_status_nack_t nacks[RLC_AM_NR_WINDOW_SIZE_12BIT];
 } rlc_am_nr_status_pdu_t;
 
 /****************************************************************************

lib/src/rlc/rlc_am_nr.cc

@@ -1149,7 +1149,7 @@ uint32_t rlc_am_nr_rx::get_status_pdu(rlc_am_nr_status_pdu_t* status, uint32_t m
 {
   std::unique_lock<std::mutex> lock(mutex, std::try_to_lock);
   if (not lock.owns_lock()) {
-    return SRSRAN_ERROR;
+    return 0;
   }
 
   status->N_nack = 0;