commit 1a9ff90de238b63d6ea02b0b0502d3bc1f3b05fe 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 4868173664de..0f1e77c281ba 100644 --- a/dom/canvas/ClientWebGLContext.cpp +++ b/dom/canvas/ClientWebGLContext.cpp @@ -4665,6 +4665,14 @@ 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; }