Fix Ruby memory leaks

- `recv_message` is not cleaned up after call
- `send_message` is not cleaned up in failure cases
- `xmalloc` ruby string is not freed after used

2 files changed, 18 insertions, 3 deletions

diff --git a/src/ruby/ext/grpc/rb_byte_buffer.c b/src/ruby/ext/grpc/rb_byte_buffer.c
index db7cac363a..52523b8319 100644
--- a/src/ruby/ext/grpc/rb_byte_buffer.c
+++ b/src/ruby/ext/grpc/rb_byte_buffer.c
@@ -52,12 +52,12 @@ grpc_byte_buffer* grpc_rb_s_to_byte_buffer(char *string, size_t length) {
 VALUE grpc_rb_byte_buffer_to_s(grpc_byte_buffer *buffer) {
   size_t length = 0;
   char *string = NULL;
+  VALUE rb_string;
   size_t offset = 0;
   grpc_byte_buffer_reader reader;
   gpr_slice next;
   if (buffer == NULL) {
     return Qnil;
-
   }
   length = grpc_byte_buffer_length(buffer);
   string = xmalloc(length + 1);
@@ -65,6 +65,9 @@ VALUE grpc_rb_byte_buffer_to_s(grpc_byte_buffer *buffer) {
   while (grpc_byte_buffer_reader_next(&reader, &next) != 0) {
     memcpy(string + offset, GPR_SLICE_START_PTR(next), GPR_SLICE_LENGTH(next));
     offset += GPR_SLICE_LENGTH(next);
+    gpr_slice_unref(next);
   }
-  return rb_str_new(string, length);
+  rb_string = rb_str_new(string, length);
+  xfree(string);
+  return rb_string;
 }
diff --git a/src/ruby/ext/grpc/rb_call.c b/src/ruby/ext/grpc/rb_call.c
index cd0aa6aaf2..b0829efdc7 100644
--- a/src/ruby/ext/grpc/rb_call.c
+++ b/src/ruby/ext/grpc/rb_call.c
@@ -551,13 +551,26 @@ static void grpc_run_batch_stack_init(run_batch_stack *st,
 /* grpc_run_batch_stack_cleanup ensures the run_batch_stack is properly
  * cleaned up */
 static void grpc_run_batch_stack_cleanup(run_batch_stack *st) {
+  size_t i = 0;
+
   grpc_metadata_array_destroy(&st->send_metadata);
   grpc_metadata_array_destroy(&st->send_trailing_metadata);
   grpc_metadata_array_destroy(&st->recv_metadata);
   grpc_metadata_array_destroy(&st->recv_trailing_metadata);
+
   if (st->recv_status_details != NULL) {
     gpr_free(st->recv_status_details);
   }
+
+  if (st->recv_message != NULL) {
+    grpc_byte_buffer_destroy(st->recv_message);
+  }
+
+  for (i = 0; i < st->op_num; i++) {
+    if (st->ops[i].op == GRPC_OP_SEND_MESSAGE) {
+      grpc_byte_buffer_destroy(st->ops[i].data.send_message);
+    }
+  }
 }
 
 /* grpc_run_batch_stack_fill_ops fills the run_batch_stack ops array from
@@ -643,7 +656,6 @@ static VALUE grpc_run_batch_stack_build_result(run_batch_stack *st) {
         break;
       case GRPC_OP_SEND_MESSAGE:
         rb_struct_aset(result, sym_send_message, Qtrue);
-        grpc_byte_buffer_destroy(st->ops[i].data.send_message);
         break;
       case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
         rb_struct_aset(result, sym_send_close, Qtrue);