2 ms·

This is not true. I don't know the details, but GPUs have something similar to page tables, so they can run untrusted tasks. The worst threat is that one could

This is not true. I don't know the details, but GPUs have something similar to page tables, so they can run untrusted tasks. The worst threat is that one could stick in an infinite loop, freezing your display output until it times out - since they don't get timesliced.

fc417fc802 1y ago
What isn't true? I stand by what I said. Having page tables (and other security features) isn't mutually exclusive with being horribly insecure in practice. CPUs have certainly had their fair share of vulnerabilities exposed within even just the past few years. I'll freely admit that I'm going off of what other people have told me. I don't do GPU driver development (or other hardware or the kernel for that matter). But the message I've encountered has been consistent in this regard. If nothing else, ask yourself why google would go to the amount of trouble that they have to develop various GPU sandboxing layers for chromeos apps.
lukan 1y ago
"The worst threat is that one could stick in an infinite loop, freezing your display output until it times out" It is not my area of expertise, but since GPUs are increasingly used for calculating things, isn't the main threat rather data leakage or even manipulation of data? WebGPU is designed to allow computation on the GPU.
- fc417fc802 1y ago
  > isn't the main threat rather data leakage or even manipulation of data? The (IMO fatally flawed) premise here is that the security boundaries enforced by the GPU hardware and driver stack would prevent that. Thus the worst case scenario is a DoS since GPUs somehow still don't seem to be very good at sharing hardware resources in scenarios that involve uncooperative parties. Note that even without GPGPU workloads there's still the obvious exfiltration target of "framebuffer containing unlocked password manager".

2 ms·

This is not true. I don't know the details, but GPUs have something similar to page tables, so they can run untrusted tasks. The worst threat is that one could

by immibis 1y ago

fc417fc802 1y ago
What isn't true? I stand by what I said. Having page tables (and other security features) isn't mutually exclusive with being horribly insecure in practice. CPUs have certainly had their fair share of vulnerabilities exposed within even just the past few years. I'll freely admit that I'm going off of what other people have told me. I don't do GPU driver development (or other hardware or the kernel for that matter). But the message I've encountered has been consistent in this regard. If nothing else, ask yourself why google would go to the amount of trouble that they have to develop various GPU sandboxing layers for chromeos apps.
lukan 1y ago
"The worst threat is that one could stick in an infinite loop, freezing your display output until it times out" It is not my area of expertise, but since GPUs are increasingly used for calculating things, isn't the main threat rather data leakage or even manipulation of data? WebGPU is designed to allow computation on the GPU.
- fc417fc802 1y ago
  > isn't the main threat rather data leakage or even manipulation of data? The (IMO fatally flawed) premise here is that the security boundaries enforced by the GPU hardware and driver stack would prevent that. Thus the worst case scenario is a DoS since GPUs somehow still don't seem to be very good at sharing hardware resources in scenarios that involve uncooperative parties. Note that even without GPGPU workloads there's still the obvious exfiltration target of "framebuffer containing unlocked password manager".