buffer: do not leak memory if buffer is too big

kvakil · danielleadams · commit 0783ddf57efc · 2022-07-25T21:44:26.000-04:00
A recent pull request changed this method to throw when the buffer was too big, but this meant that the `free` finalizer would never get called, leading to a memory leak. A previous version of this diff included a test provoking this behavior with `v8.serialize`, but it unfortunately kept triggering the OOM killer, so it was removed. Refs: #40243 PR-URL: #43938 Reviewed-By: Darshan Sen <raisinten@gmail.com> Reviewed-By: Tobias Nießen <tniessen@tnie.de> Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
diff --git a/src/node_buffer.cc b/src/node_buffer.cc
@@ -497,6 +497,7 @@ MaybeLocal<Object> New(Environment* env,
     if (length > kMaxLength) {
       Isolate* isolate(env->isolate());
       isolate->ThrowException(ERR_BUFFER_TOO_LARGE(isolate));
+      free(data);
       return Local<Object>();
     }
   }

Original file line number	Diff line number	Diff line change
`@@ -497,6 +497,7 @@ MaybeLocal<Object> New(Environment* env,`
`497`	`497`	`if (length > kMaxLength) {`
`498`	`498`	`Isolate* isolate(env->isolate());`
`499`	`499`	`isolate->ThrowException(ERR_BUFFER_TOO_LARGE(isolate));`
	`500`	`+ free(data);`
`500`	`501`	`return Local<Object>();`
`501`	`502`	`}`
`502`	`503`	`}`