Bug 50048 – Need to initialize destination variables before calling GL

• Component: WebGL
• Status: RESOLVED FIXED

[Gregg Tavares]

Need to initialize variables before calling GL because if GL has lost the context then those variables will remain uninitialized.

For example

  GLsize len;
  glGetProgramiv(service_id_, GL_INFO_LOG_LENGTH, &len);
  char* dst = new char[len];

In the case above, if GL has lost the const, len will be uninitialized and quite possibly try to allocate a large amount of memory which may easily cause a crash. The solution is to always initialized the variables.

  GLsize len = 0;  <-----
  glGetProgramiv(service_id_, GL_INFO_LOG_LENGTH, &len);
  char* dst = new char[len];

[Gregg Tavares]

I have a patch to fix the places in WebKit where this is an issue.

[Kenneth Russell]

It would be great if you could submit your patch. Run prepare-ChangeLog, edit the modified ChangeLogs appropriately, and webkit-patch upload to upload it. See http://webkit.org/coding/contributing.html .

[Gregg Tavares]

Created attachment 75075 [details]
Patch

[Kenneth Russell]

Comment on attachment 75075 [details]
Patch

The code changes look fine, and sorry for the nitpick, but could you please change your editor's settings to not modify existing whitespace, and regenerate the patch? I've been advised by other WebKit reviewers that whitespace changes should not be done in conjunction with code changes. It would be great if you would file a separate bug and submit a patch just for the whitespace cleanups.

[Gregg Tavares]

Created attachment 75447 [details]
Patch

[David Levin]

Comment on attachment 75447 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=75447&action=review

> WebCore/platform/graphics/chromium/LayerRendererChromium.cpp:846
> +    m_maxTextureSize = 0;

I'm surprised this isn't initialized in the constructor.

[WebKit Commit Bot]

Comment on attachment 75447 [details]
Patch

Clearing flags on attachment: 75447

Committed r73244: <http://trac.webkit.org/changeset/73244>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.