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by haasn 3614 days ago
> Which are ...?

I'm not an expert, but I wonder if this means you could restrict GPU access to the master process only (for the sake of hardware-accelerated compositing) without needing to expose it to the website-facing process (due to the security vulnerabilities in GPU drivers).
1 comments
ryuuchin 3614 days ago
Angle (the OpenGL -> DirectX thingy) actually acts as a sanitizer for GPU commands so in a sense browsers which use Angle already have some protection over this. While I think complete protection is impossible through the use of Angle and GPU process I think you reduce it as much as you can since you can't control the driver itself aside from what protections Windows gives you by default.
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haasn 3614 days ago
That implies running Windows, though.

My biggest problem with GPU drivers is that they stick out like a sore thumb on a hardened system. All the protection and isolation in the world won't help you when you have a stock-compiled, PaX-disabled blob loaded into your binary that communicates directly with the kernel.

For this reason and this reason alone, I am forced to basically limit OpenGL access to X.org and mpv.

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ryuuchin 3614 days ago
> That implies running Windows, though.

Indeed. My knowledge on Linux is pretty limited but I seem to remember that Nvidia fixed something which let you use Pax/grsecurity protections you otherwise couldn't. This still implies loading a binary blob but certain kernel protections could still help you IIRC (DEP?). I could be misremembering. I can't check since grsecurity set their twitter to protected.

I'm not sure what Chrome does aside from having a separate GPU process and whether or not any sanitizing takes place. They're pretty good with stuff like that so it would surprise me if some amount of protection wasn't offered.

Edit: There are some patches from the Pax folks for Nvidia drivers which I believe help with PAX_USERCOPY[1][2]? Although that may just be for getting it working...

[1] https://grsecurity.net/~paxguy1/

[2] https://grsecurity.net/~paxguy1/nvidia-drivers-367.35-pax.pa... (example)

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haasn 3614 days ago
Those patches are for running the nvidia kernel driver in a PaX-enabled kernel. It doesn't help you protect the actual libGL.so, which my concern was about.

(Indeed, I have to use those patches otherwise the nvidia kernel module wouldn't compile)

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