Re: [PATCH] KVM: arm64: Prevent access to vCPU events before init

On Tue, 30 Sep 2025 01:52:37 -0700, Oliver Upton wrote:

Another day, another syzkaller bug. KVM erroneously allows userspace to pend vCPU events for a vCPU that hasn't been initialized yet, leading to KVM interpreting a bunch of uninitialized garbage for routing / injecting the exception.

In one case the injection code and the hyp disagree on whether the vCPU has a 32bit EL1 and put the vCPU into an illegal mode for AArch64, tripping the BUG() in exception_target_el() during the next injection:

[...]

Applied to fixes, thanks!

[1/1] KVM: arm64: Prevent access to vCPU events before init commit: cc96679f3c0348bf8450a5c84b71bb1351c027f9

Cheers,

M.