protect bpool from buffer pollution by invalid buffers (#20342)

cmd/erasure-decode.go

@@ -48,14 +48,14 @@ func newParallelReader(readers []io.ReaderAt, e Erasure, offset, totalLength int
 		r2b[i] = i
 	}
 	bufs := make([][]byte, len(readers))
-	// Fill buffers
-	b := globalBytePoolCap.Load().Get()
 	shardSize := int(e.ShardSize())
-	if cap(b) < len(readers)*shardSize {
-		// We should always have enough capacity, but older objects may be bigger.
-		globalBytePoolCap.Load().Put(b)
-		b = nil
-	} else {
+	var b []byte
+
+	// We should always have enough capacity, but older objects may be bigger
+	// we do not need stashbuffer for them.
+	if globalBytePoolCap.Load().WidthCap() >= len(readers)*shardSize {
+		// Fill buffers
+		b = globalBytePoolCap.Load().Get()
 		// Seed the buffers.
 		for i := range bufs {
 			bufs[i] = b[i*shardSize : (i+1)*shardSize]

cmd/object-api-deleteobject_test.go

@@ -93,14 +93,18 @@ func testDeleteObject(obj ObjectLayer, instanceType string, t TestErrHandler) {
 			md5Bytes := md5.Sum([]byte(object.content))
 			oi, err := obj.PutObject(context.Background(), testCase.bucketName, object.name, mustGetPutObjReader(t, strings.NewReader(object.content),
 				int64(len(object.content)), hex.EncodeToString(md5Bytes[:]), ""), ObjectOptions{})
-			t.Log(oi)
 			if err != nil {
+				t.Log(oi)
 				t.Fatalf("%s : %s", instanceType, err.Error())
 			}
 		}
 
 		oi, err := obj.DeleteObject(context.Background(), testCase.bucketName, testCase.pathToDelete, ObjectOptions{})
-		t.Log(oi, err)
+		if err != nil && !isErrObjectNotFound(err) {
+			t.Log(oi)
+			t.Errorf("Test %d: %s:  Expected to pass, but failed with: <ERROR> %s", i+1, instanceType, err)
+			continue
+		}
 
 		result, err := obj.ListObjects(context.Background(), testCase.bucketName, "", "", "", 1000)
 		if err != nil {