Fix some memory errors triggered by allocation failures (ntop#1995)

Some low hanging fruits found using nallocfuzz.
See: https://github.com/catenacyber/nallocfuzz
See: google/oss-fuzz#9902

Most of these errors are quite trivial to fix; the only exception is the
stuff in the uthash.
If the insertion fails (because of an allocation failure), we need to
avoid some memory leaks. But the only way to check if the `HASH_ADD_*`
failed, is to perform a new lookup: a bit costly, but we don't use that
code in any critical data-path.

example/reader_util.c

@@ -116,14 +116,14 @@ u_int16_t max_pattern_len = 8;
 
 /* *********************************************************** */
 
-void ndpi_analyze_payload(struct ndpi_flow_info *flow,
-			  u_int8_t src_to_dst_direction,
-			  u_int8_t *payload,
-			  u_int16_t payload_len,
-			  u_int32_t packet_id) {
-  struct payload_stats *ret;
-  struct flow_id_stats *f;
-  struct packet_id_stats *p;
+int ndpi_analyze_payload(struct ndpi_flow_info *flow,
+			 u_int8_t src_to_dst_direction,
+			 u_int8_t *payload,
+			 u_int16_t payload_len,
+			 u_int32_t packet_id) {
+  struct payload_stats *ret, *ret_found;
+  struct flow_id_stats *f, *f_found;
+  struct packet_id_stats *p, *p_found;
 
 #ifdef DEBUG_PAYLOAD
   u_int16_t i;
@@ -135,11 +135,11 @@ void ndpi_analyze_payload(struct ndpi_flow_info *flow,
   HASH_FIND(hh, pstats, payload, payload_len, ret);
   if(ret == NULL) {
     if((ret = (struct payload_stats*)ndpi_calloc(1, sizeof(struct payload_stats))) == NULL)
-      return; /* OOM */
+      return -1; /* OOM */
 
     if((ret->pattern = (u_int8_t*)ndpi_malloc(payload_len)) == NULL) {
       ndpi_free(ret);
-      return;
+      return -1;
     }
 
     memcpy(ret->pattern, payload, payload_len);
@@ -148,6 +148,13 @@ void ndpi_analyze_payload(struct ndpi_flow_info *flow,
 
     HASH_ADD(hh, pstats, pattern[0], payload_len, ret);
 
+    HASH_FIND(hh, pstats, payload, payload_len, ret_found);
+    if(ret_found == NULL) { /* The insertion failed (because of a memory allocation error) */
+      ndpi_free(ret->pattern);
+      ndpi_free(ret);
+      return -1;
+    }
+
 #ifdef DEBUG_PAYLOAD
     printf("Added element [total: %u]\n", HASH_COUNT(pstats));
 #endif
@@ -159,20 +166,32 @@ void ndpi_analyze_payload(struct ndpi_flow_info *flow,
   HASH_FIND_INT(ret->flows, &flow->flow_id, f);
   if(f == NULL) {
     if((f = (struct flow_id_stats*)ndpi_calloc(1, sizeof(struct flow_id_stats))) == NULL)
-      return; /* OOM */
+      return -1; /* OOM */
 
     f->flow_id = flow->flow_id;
     HASH_ADD_INT(ret->flows, flow_id, f);
+
+    HASH_FIND_INT(ret->flows, &flow->flow_id, f_found);
+    if(f_found == NULL) { /* The insertion failed (because of a memory allocation error) */
+      ndpi_free(f);
+      return -1;
+    }
   }
 
   HASH_FIND_INT(ret->packets, &packet_id, p);
   if(p == NULL) {
     if((p = (struct packet_id_stats*)ndpi_calloc(1, sizeof(struct packet_id_stats))) == NULL)
-      return; /* OOM */
+      return -1; /* OOM */
     p->packet_id = packet_id;
 
     HASH_ADD_INT(ret->packets, packet_id, p);
+
+    HASH_FIND_INT(ret->packets, &packet_id, p_found);
+    if(p_found == NULL) { /* The insertion failed (because of a memory allocation error) */
+      ndpi_free(p);
+    }
   }
+  return 0;
 }
 
 /* *********************************************************** */
@@ -199,7 +218,12 @@ void ndpi_payload_analyzer(struct ndpi_flow_info *flow,
   for(i=0; i<scan_len; i++) {
     for(j=min_pattern_len; j <= max_pattern_len; j++) {
       if((i+j) < payload_len) {
-	ndpi_analyze_payload(flow, src_to_dst_direction, &payload[i], j, packet_id);
+	if(ndpi_analyze_payload(flow, src_to_dst_direction, &payload[i], j, packet_id) == -1) {
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+          /* Avoid too much logging while fuzzing */
+          LOG(NDPI_LOG_ERROR, "Error ndpi_analyze_payload (allocation failure)\n");
+#endif
+	}
       }
     }
   }
@@ -960,6 +984,12 @@ static struct ndpi_flow_info *get_ndpi_flow_info(struct ndpi_workflow * workflow
       if(enable_flow_stats) {
         newflow->entropy = ndpi_calloc(1, sizeof(struct ndpi_entropy));
         newflow->last_entropy = ndpi_calloc(1, sizeof(struct ndpi_entropy));
+        if(!newflow->entropy || !newflow->last_entropy) {
+          ndpi_tdelete(newflow, &workflow->ndpi_flows_root[idx], ndpi_workflow_node_cmp);
+          ndpi_flow_info_free_data(newflow);
+          ndpi_free(newflow);
+          return(NULL);
+        }
         newflow->entropy->src2dst_pkt_len[newflow->entropy->src2dst_pkt_count] = l4_data_len;
         newflow->entropy->src2dst_pkt_time[newflow->entropy->src2dst_pkt_count] = when;
         if(newflow->entropy->src2dst_pkt_count == 0) {

fuzz/fuzz_ds_ahocorasick.cpp

@@ -133,7 +133,8 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
 
   f = fopen("/dev/null", "w");
   ac_automata_dump(a, f);
-  fclose(f);
+  if (f)
+    fclose(f);
 
   ac_automata_get_stats(a, &stats);
 

fuzz/fuzz_libinjection.c

@@ -12,6 +12,8 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   /* Libinjection: it wants null-terminated string */
 
   query = malloc(size + 1);
+  if (!query)
+    return 0;
   memcpy(query, data, size);
   query[size] = '\0';
 

fuzz/fuzz_process_packet.c

@@ -5,6 +5,7 @@
 #include <stdio.h>
 
 struct ndpi_detection_module_struct *ndpi_info_mod = NULL;
+struct ndpi_flow_struct ndpi_flow;
 static ndpi_serializer json_serializer = {};
 static ndpi_serializer csv_serializer = {};
 
@@ -18,24 +19,23 @@ int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
     ndpi_init_serializer(&csv_serializer, ndpi_serialization_format_csv);
   }
 
-  struct ndpi_flow_struct *ndpi_flow = ndpi_flow_malloc(SIZEOF_FLOW_STRUCT);
-  memset(ndpi_flow, 0, SIZEOF_FLOW_STRUCT);
+  memset(&ndpi_flow, 0, SIZEOF_FLOW_STRUCT);
   ndpi_protocol detected_protocol =
-    ndpi_detection_process_packet(ndpi_info_mod, ndpi_flow, Data, Size, 0, NULL);
+    ndpi_detection_process_packet(ndpi_info_mod, &ndpi_flow, Data, Size, 0, NULL);
   ndpi_protocol guessed_protocol =
-    ndpi_detection_giveup(ndpi_info_mod, ndpi_flow, 1, &protocol_was_guessed);
+    ndpi_detection_giveup(ndpi_info_mod, &ndpi_flow, 1, &protocol_was_guessed);
 
   ndpi_reset_serializer(&json_serializer);
   ndpi_reset_serializer(&csv_serializer);
   if (protocol_was_guessed == 0)
   {
-    ndpi_dpi2json(ndpi_info_mod, ndpi_flow, detected_protocol, &json_serializer);
-    ndpi_dpi2json(ndpi_info_mod, ndpi_flow, detected_protocol, &csv_serializer);
+    ndpi_dpi2json(ndpi_info_mod, &ndpi_flow, detected_protocol, &json_serializer);
+    ndpi_dpi2json(ndpi_info_mod, &ndpi_flow, detected_protocol, &csv_serializer);
   } else {
-    ndpi_dpi2json(ndpi_info_mod, ndpi_flow, guessed_protocol, &json_serializer);
-    ndpi_dpi2json(ndpi_info_mod, ndpi_flow, guessed_protocol, &csv_serializer);
+    ndpi_dpi2json(ndpi_info_mod, &ndpi_flow, guessed_protocol, &json_serializer);
+    ndpi_dpi2json(ndpi_info_mod, &ndpi_flow, guessed_protocol, &csv_serializer);
   }
-  ndpi_free_flow(ndpi_flow);
+  ndpi_free_flow_data(&ndpi_flow);
 
   return 0;
 }

src/lib/ndpi_main.c

@@ -2509,6 +2509,9 @@ static int ndpi_add_host_ip_subprotocol(struct ndpi_detection_module_struct *ndp
   u_int16_t port = 0; /* Format ip:8.248.73.247:443 */
   char *double_column;
 
+  if(!ndpi_str->protocols_ptree)
+    return(-1);
+
   if(ptr) {
     ptr[0] = '\0';
     ptr++;
@@ -3674,6 +3677,9 @@ int ndpi_add_ip_risk_mask(struct ndpi_detection_module_struct *ndpi_str,
 			  char *ip, ndpi_risk mask) {
   char *saveptr, *addr = strtok_r(ip, "/", &saveptr);
 
+  if(!ndpi_str->ip_risk_mask_ptree)
+    return(-3);
+
   if(addr) {
     char *cidr = strtok_r(NULL, "\n", &saveptr);
     struct in_addr pin;
@@ -6483,6 +6489,9 @@ int ndpi_load_ip_category(struct ndpi_detection_module_struct *ndpi_str,
   char *ptr;
   char ipbuf[64];
 
+  if(!ndpi_str->custom_categories.ipAddresses_shadow)
+    return(-1);
+
   strncpy(ipbuf, ip_address_and_mask, sizeof(ipbuf));
   ipbuf[sizeof(ipbuf) - 1] = '\0';
 
@@ -6618,7 +6627,9 @@ int ndpi_fill_ip_protocol_category(struct ndpi_detection_module_struct *ndpi_str
 
   ret->custom_category_userdata = NULL;
 
-  if(ndpi_str->custom_categories.categories_loaded) {
+  if(ndpi_str->custom_categories.categories_loaded &&
+     ndpi_str->custom_categories.ipAddresses) {
+
     ndpi_prefix_t prefix;
     ndpi_patricia_node_t *node;
 

src/lib/ndpi_utils.c

@@ -2288,6 +2288,7 @@ int ndpi_hash_add_entry(ndpi_str_hash **h, char *key, u_int8_t key_len, void *va
 {
   struct ndpi_str_hash_private **h_priv = (struct ndpi_str_hash_private **)h;
   struct ndpi_str_hash_private *new = ndpi_calloc(1, sizeof(*new));
+  struct ndpi_str_hash_private *found;
   unsigned int hash_value;
 
   if (new == NULL)
@@ -2299,6 +2300,14 @@ int ndpi_hash_add_entry(ndpi_str_hash **h, char *key, u_int8_t key_len, void *va
   new->hash = hash_value;
   new->value = value;
   HASH_ADD_INT(*h_priv, hash, new);
+
+  HASH_FIND_INT(*h_priv, &hash_value, found);
+  if (found == NULL) /* The insertion failed (because of a memory allocation error) */
+  {
+    ndpi_free(new);
+    return 1;
+  }
+
   return 0;
 }
 

src/lib/third_party/include/uthash.h

@@ -101,7 +101,7 @@ do {
 #endif
 
 #ifndef HASH_NONFATAL_OOM
-#define HASH_NONFATAL_OOM 0
+#define HASH_NONFATAL_OOM 1
 #endif
 
 #if HASH_NONFATAL_OOM