Re:Firefox does not have a well-designed privsep model
by yellowapple on Monday June 11, 2018 @08:42PM
(#17289857)
"They seem to be willing to break compatibility as illustrated by them ditching their massive library of legacy extensions."
My guess is that Theo's talking less about the XUL → WebExtensions transition and more about breaking compatibility with actual websites (and specifically the Javascript running on / loaded by said websites).
"then describes a security feature they have implemented for JIT that Chrome has yet to provide."
And immediately afterward describes how that security feature is actually implemented in a way that's relatively easy to circumvent (Firefox's JIT uses two "views" around the relevant chunk of memory - one writable, one executable - in order to technically implement W^X for each of those views without actually enforcing it for the underlying memory itself).
That doesn't sound much like self-contradiction to me; that sounds more like preemptively addressing the inevitable argument of "well Firefox does W^X on OpenBSD so it's gotta be more secure than Chrome, right?".
My guess is that Theo's talking less about the XUL → WebExtensions transition and more about breaking compatibility with actual websites (and specifically the Javascript running on / loaded by said websites).
"then describes a security feature they have implemented for JIT that Chrome has yet to provide."
And immediately afterward describes how that security feature is actually implemented in a way that's relatively easy to circumvent (Firefox's JIT uses two "views" around the relevant chunk of memory - one writable, one executable - in order to technically implement W^X for each of those views without actually enforcing it for the underlying memory itself).
That doesn't sound much like self-contradiction to me; that sounds more like preemptively addressing the inevitable argument of "well Firefox does W^X on OpenBSD so it's gotta be more secure than Chrome, right?".