[CRE-39] (fix): Add more guards & nil checks to WASM compute

pkg/workflows/wasm/host/module.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"regexp"
 
 	"strings"
 	"sync"
@@ -383,6 +384,9 @@ func (m *Module) Run(ctx context.Context, request *wasmpb.Request) (*wasmpb.Resp
 }
 
 func containsCode(err error, code int) bool {
+	if err == nil {
+		return false
+	}
 	return strings.Contains(err.Error(), fmt.Sprintf("exit status %d", code))
 }
 
@@ -596,21 +600,24 @@ func createLogFn(logger logger.Logger) func(caller *wasmtime.Caller, ptr int32,
 			args = append(args, k, v)
 		}
 
+		reg, _ := regexp.Compile(`[^\w]`)
+		sanitizedMsg := reg.ReplaceAllString(msg, " ")
+
 		switch level {
 		case "debug":
-			logger.Debugw(msg, args...)
+			logger.Debugw(sanitizedMsg, args...)
 		case "info":
-			logger.Infow(msg, args...)
+			logger.Infow(sanitizedMsg, args...)
 		case "warn":
-			logger.Warnw(msg, args...)
+			logger.Warnw(sanitizedMsg, args...)
 		case "error":
-			logger.Errorw(msg, args...)
+			logger.Errorw(sanitizedMsg, args...)
 		case "panic":
-			logger.Panicw(msg, args...)
+			logger.Panicw(sanitizedMsg, args...)
 		case "fatal":
-			logger.Fatalw(msg, args...)
+			logger.Fatalw(sanitizedMsg, args...)
 		default:
-			logger.Infow(msg, args...)
+			logger.Infow(sanitizedMsg, args...)
 		}
 	}
 }

pkg/workflows/wasm/sdk.go

@@ -97,6 +97,9 @@ func createEmitFn(
 			return NewEmissionError(fmt.Errorf("metadata is required to emit"))
 		}
 
+		if labels == nil {
+			return NewEmissionError(fmt.Errorf("labels must be provided"))
+		}
 		labels, err := toEmitLabels(sdkConfig.Metadata, labels)
 		if err != nil {
 			return NewEmissionError(err)
@@ -120,14 +123,23 @@ func createEmitFn(
 		// Prepare the request to be sent to the host memory by allocating space for the
 		// response and response length buffers.
 		respBuffer := make([]byte, sdkConfig.MaxFetchResponseSizeBytes)
-		respptr, _ := bufferToPointerLen(respBuffer)
+		respptr, _, err := bufferToPointerLen(respBuffer)
+		if err != nil {
+			return err
+		}
 
 		resplenBuffer := make([]byte, uint32Size)
-		resplenptr, _ := bufferToPointerLen(resplenBuffer)
+		resplenptr, _, err := bufferToPointerLen(resplenBuffer)
+		if err != nil {
+			return err
+		}
 
 		// The request buffer is the wasm memory, get a pointer to the first element and the length
 		// of the protobuf message.
-		reqptr, reqptrlen := bufferToPointerLen(b)
+		reqptr, reqptrlen, err := bufferToPointerLen(b)
+		if err != nil {
+			return err
+		}
 
 		// Emit the message via the method imported from the host
 		errno := emit(respptr, resplenptr, reqptr, reqptrlen)
@@ -188,13 +200,22 @@ func createFetchFn(
 		if err != nil {
 			return sdk.FetchResponse{}, fmt.Errorf("failed to marshal fetch request: %w", err)
 		}
-		reqptr, reqptrlen := bufferToPointerLen(b)
+		reqptr, reqptrlen, err := bufferToPointerLen(b)
+		if err != nil {
+			return sdk.FetchResponse{}, err
+		}
 
 		respBuffer := make([]byte, sdkConfig.MaxFetchResponseSizeBytes)
-		respptr, _ := bufferToPointerLen(respBuffer)
+		respptr, _, err := bufferToPointerLen(respBuffer)
+		if err != nil {
+			return sdk.FetchResponse{}, err
+		}
 
 		resplenBuffer := make([]byte, uint32Size)
-		resplenptr, _ := bufferToPointerLen(resplenBuffer)
+		resplenptr, _, err := bufferToPointerLen(resplenBuffer)
+		if err != nil {
+			return sdk.FetchResponse{}, err
+		}
 
 		errno := fetch(respptr, resplenptr, reqptr, reqptrlen)
 		if errno != 0 {
@@ -229,8 +250,11 @@ func createFetchFn(
 }
 
 // bufferToPointerLen returns a pointer to the first element of the buffer and the length of the buffer.
-func bufferToPointerLen(buf []byte) (unsafe.Pointer, int32) {
-	return unsafe.Pointer(&buf[0]), int32(len(buf))
+func bufferToPointerLen(buf []byte) (unsafe.Pointer, int32, error) {
+	if len(buf) == 0 {
+		return nil, 0, fmt.Errorf("buffer cannot be empty")
+	}
+	return unsafe.Pointer(&buf[0]), int32(len(buf)), nil
 }
 
 // toEmitLabels ensures that the required metadata is present in the labels map
@@ -247,6 +271,10 @@ func toEmitLabels(md *capabilities.RequestMetadata, labels map[string]string) (m
 		return nil, fmt.Errorf("must provide workflow owner to emit event")
 	}
 
+	if md.WorkflowExecutionID == "" {
+		return nil, fmt.Errorf("must provide workflow owner to emit event")
+	}
+
 	labels[events.LabelWorkflowExecutionID] = md.WorkflowExecutionID
 	labels[events.LabelWorkflowOwner] = md.WorkflowOwner
 	labels[events.LabelWorkflowID] = md.WorkflowID