[Impact]
Similar to bug 1987541, where shim may execute GRUB w/ polluted instruction cache, GRUB itself also fails to flush the instruction cache for the kernel memory before starting it. This is believed to be the source of some rare crashes seen executing instructions in the kernel EFI stub.
[Test Case]
Put an arm64 server in a reboot loop and watch for a crash (synchronous exception abort) after GRUB has started executing the kernel.
[Impact]
Similar to bug 1987541, where shim may execute GRUB w/ polluted instruction cache, GRUB itself also fails to flush the instruction cache for the kernel memory before starting it. This is believed to be the source of some rare crashes seen executing instructions in the kernel EFI stub.
[Test Case]
Put an arm64 server in a reboot loop and watch for a crash (synchronous exception abort) after GRUB has started executing the kernel.
[Fix] /github. com/rhboot/ grub2/pull/ 107
https:/
[What could go wrong]
The only risk I can identify is possibly-measurable performance impact to booting the kernel.