commit d00bb8e095e7aecd35e8e4893343cb5afc382c3b Author: Georg Koppen gk@torproject.org Date: Wed May 29 12:29:19 2019 +0000

Bug 30541: Disable WebGL readPixel() for web content --- dom/canvas/ClientWebGLContext.cpp | 8 ++++++++ 1 file changed, 8 insertions(+)

diff --git a/dom/canvas/ClientWebGLContext.cpp b/dom/canvas/ClientWebGLContext.cpp index 01f68aa795b7..8261829e2250 100644 --- a/dom/canvas/ClientWebGLContext.cpp +++ b/dom/canvas/ClientWebGLContext.cpp @@ -4115,6 +4115,14 @@ bool ClientWebGLContext::ReadPixels_SharedPrecheck( return false; }

+ // Security check passed, but don't let content readPixel calls through for + // now, if Resist Fingerprinting Mode is enabled. + if (nsContentUtils::ResistFingerprinting(aCallerType)) { + JsWarning("readPixels: Not allowed in Resist Fingerprinting Mode"); + out_error.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR); + return false; + } + return true; }