Use heap memory instead of stack for large variables

The default stack size for musl-libc is 128kb. Therefore we should try to keep stack
allocations well below this limit in order to avoid stack overflows.

other/bootstrap_daemon/docker/tox-bootstrapd.sha256

@@ -1 +1 @@
-16d62d5c5aa261d6efefbe8e94cc25a68c76ea923ae92ce56b0d22b32326ae0b  /usr/local/bin/tox-bootstrapd
+ca03a05f92fb3169c588ff0894c7a1d4466d71c36e3a7ddbe804797f15d6c126  /usr/local/bin/tox-bootstrapd

toxav/audio.c

@@ -126,7 +126,12 @@ void ac_iterate(ACSession *ac)
     /* TODO(mannol): fix this and jitter buffering */
 
     /* Enough space for the maximum frame size (120 ms 48 KHz stereo audio) */
-    int16_t temp_audio_buffer[AUDIO_MAX_BUFFER_SIZE_PCM16 * AUDIO_MAX_CHANNEL_COUNT];
+    int16_t *temp_audio_buffer = (int16_t *)malloc(AUDIO_MAX_BUFFER_SIZE_PCM16 * AUDIO_MAX_CHANNEL_COUNT * sizeof(int16_t));
+
+    if (temp_audio_buffer == nullptr) {
+        LOGGER_ERROR(ac->log, "Failed to allocate memory for audio buffer");
+        return;
+    }
 
     pthread_mutex_lock(ac->queue_mutex);
     struct JitterBuffer *const j_buf = (struct JitterBuffer *)ac->j_buf;
@@ -195,10 +200,14 @@ void ac_iterate(ACSession *ac)
                     ac->lp_sampling_rate, ac->acb_user_data);
         }
 
+        free(temp_audio_buffer);
+
         return;
     }
 
     pthread_mutex_unlock(ac->queue_mutex);
+
+    free(temp_audio_buffer);
 }
 
 int ac_queue_message(Mono_Time *mono_time, void *acp, struct RTPMessage *msg)

toxcore/DHT.c

@@ -2830,7 +2830,12 @@ void dht_save(const DHT *dht, uint8_t *data)
     /* get right offset. we write the actual header later. */
     data = state_write_section_header(data, DHT_STATE_COOKIE_TYPE, 0, 0);
 
-    Node_format clients[MAX_SAVED_DHT_NODES];
+    Node_format *clients = (Node_format *)malloc(MAX_SAVED_DHT_NODES * sizeof(Node_format));
+
+    if (clients == nullptr) {
+        LOGGER_ERROR(dht->log, "could not allocate %u nodes", MAX_SAVED_DHT_NODES);
+        return;
+    }
 
     uint32_t num = 0;
 
@@ -2873,6 +2878,8 @@ void dht_save(const DHT *dht, uint8_t *data)
 
     state_write_section_header(old_data, DHT_STATE_COOKIE_TYPE, pack_nodes(data, sizeof(Node_format) * num, clients, num),
                                DHT_STATE_TYPE_NODES);
+
+    free(clients);
 }
 
 /* Bootstrap from this number of nodes every time dht_connect_after_load() is called */