sbi/nrf: This patch improves robustness of SBI client creation, HTTP parsing,

and NRF NFProfile validation by adding defensive checks and safer
memory handling.

Key changes:

1) Prevent client creation without endpoint information
   - Added error logging when NF instance lacks FQDN/IP endpoint data.
   - Avoids creating invalid SBI clients with incomplete connectivity info.

2) Enforce query parameter limits
   - Added explicit bounds check against MAX_NUM_OF_PARAM_IN_QUERY.
   - Returns HTTP 400 instead of triggering fatal assertion.
   - Prevents potential DoS via excessive query parameters.

3) Safer HTTP body memory handling
   - Introduced temporary buffer for malloc/realloc results.
   - Prevents loss of original pointer on realloc failure.
   - Returns NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE on overflow.
   - Improves resilience against large/fragmented payload attacks.

4) Validate NFProfile endpoint presence during registration
   - Rejects NFProfile lacking FQDN, IPv4, and IPv6 addresses.
   - Returns HTTP 400 with explicit error message.
   - Prevents NRF from storing unreachable NF instances.

Overall, this patch strengthens SBI stability and protects against
resource exhaustion, malformed requests, and invalid NF registrations.

Issues: #4243, #4244, #4245

lib/sbi/context.c

@@ -2052,7 +2052,8 @@ static ogs_sbi_client_t *nf_instance_find_client(
                 return NULL;
             }
         }
-    }
+    } else
+        ogs_error("No endpoint info, skip client creation");
 
     return client;
 }

lib/sbi/nghttp2-server.c

@@ -1397,6 +1397,21 @@ static int on_header(nghttp2_session *session, const nghttp2_frame *frame,
 
         j = 0;
         while(params[j].key && params[j].val) {
+            if (j >= MAX_NUM_OF_PARAM_IN_QUERY) {
+                ogs_error("Too many query params (max=%d)",
+                        MAX_NUM_OF_PARAM_IN_QUERY);
+                ogs_sbi_server_send_error(stream,
+                        OGS_SBI_HTTP_STATUS_BAD_REQUEST, NULL,
+                        "Too many query parameters", NULL, NULL);
+
+                ogs_free(query);
+
+                ogs_free(namestr);
+                ogs_free(valuestr);
+
+                return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
+            }
+
             if (strlen(params[j].key))
                 ogs_sbi_header_set(request->http.params,
                         params[j].key, params[j].val);
@@ -1406,12 +1421,6 @@ static int on_header(nghttp2_session *session, const nghttp2_frame *frame,
             j++;
         }
 
-        if (j >= MAX_NUM_OF_PARAM_IN_QUERY+1) {
-            ogs_fatal("Maximum number(%d) of query params reached",
-                    MAX_NUM_OF_PARAM_IN_QUERY);
-            ogs_assert_if_reached();
-        }
-
         ogs_free(query);
 
     } else if (namebuf.len == sizeof(METHOD) - 1 &&
@@ -1439,6 +1448,7 @@ static int on_data_chunk_recv(nghttp2_session *session, uint8_t flags,
 {
     ogs_sbi_stream_t *stream = NULL;
     ogs_sbi_request_t *request = NULL;
+    char *content = NULL;
 
     size_t offset = 0;
 
@@ -1460,24 +1470,26 @@ static int on_data_chunk_recv(nghttp2_session *session, uint8_t flags,
         ogs_assert(request->http.content_length == 0);
         ogs_assert(offset == 0);
 
-        request->http.content = (char*)ogs_malloc(len + 1);
+        content = (char*)ogs_malloc(len + 1);
     } else {
         ogs_assert(request->http.content_length != 0);
 
-        request->http.content = (char*)ogs_realloc(
+        content = (char*)ogs_realloc(
                 request->http.content, request->http.content_length + len + 1);
     }
 
-    if (!request->http.content) {
+    if (!content) {
         stream->memory_overflow = true;
 
         ogs_error("Overflow : Content-Length[%d], len[%d]",
                     (int)request->http.content_length, (int)len);
         ogs_log_hexdump(OGS_LOG_ERROR, data, len);
 
-        return 0;
+        return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
     }
 
+    request->http.content = content;
+
     offset = request->http.content_length;
     request->http.content_length += len;
 

src/nrf/nnrf-handler.c

@@ -86,6 +86,19 @@ bool nrf_nnrf_handle_nf_register(ogs_sbi_nf_instance_t *nf_instance,
         return false;
     }
 
+    if (!NFProfile->fqdn &&
+        (!NFProfile->ipv4_addresses || !NFProfile->ipv4_addresses->first) &&
+        (!NFProfile->ipv6_addresses || !NFProfile->ipv6_addresses->first)) {
+        ogs_error("NFProfile missing endpoint: id=%s type=%s",
+                nf_instance->id,
+                OpenAPI_nf_type_ToString(NFProfile->nf_type));
+        ogs_assert(true ==
+            ogs_sbi_server_send_error(
+                stream, OGS_SBI_HTTP_STATUS_BAD_REQUEST,
+                recvmsg, "NFProfile missing endpoint", nf_instance->id, NULL));
+        return false;
+    }
+
     /* Validate the PLMN-ID against configured serving PLMN-IDs */
     if (NFProfile->plmn_list) {
         /* Set PLMN status to invalid */