Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: Handle kvm_arm_init failure correctly in finalize_pkvm

Currently there is no synchronisation between finalize_pkvm() and kvm_arm_init() initcalls. The finalize_pkvm() proceeds happily even if kvm_arm_init() fails resulting in the following warning on all the CPUs and eventually a HYP panic:

| kvm [1]: IPA Size Limit: 48 bits | kvm [1]: Failed to init hyp memory protection | kvm [1]: error initializing Hyp mode: -22 | | <snip> | | WARNING: CPU: 0 PID: 0 at arch/arm64/kvm/pkvm.c:226 _kvm_host_prot_finalize+0x30/0x50 | Modules linked in: | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0 #237 | Hardware name: FVP Base RevC (DT) | pstate: 634020c5 (nZCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) | pc : _kvm_host_prot_finalize+0x30/0x50 | lr : __flush_smp_call_function_queue+0xd8/0x230 | | Call trace: | _kvm_host_prot_finalize+0x3c/0x50 | on_each_cpu_cond_mask+0x3c/0x6c | pkvm_drop_host_privileges+0x4c/0x78 | finalize_pkvm+0x3c/0x5c | do_one_initcall+0xcc/0x240 | do_initcall_level+0x8c/0xac | do_initcalls+0x54/0x94 | do_basic_setup+0x1c/0x28 | kernel_init_freeable+0x100/0x16c | kernel_init+0x20/0x1a0 | ret_from_fork+0x10/0x20 | Failed to finalize Hyp protection: -22 | dtb=fvp-base-revc.dtb | kvm [95]: nVHE hyp BUG at: arch/arm64/kvm/hyp/nvhe/mem_protect.c:540! | kvm [95]: nVHE call trace: | kvm [95]: [<ffff800081052984>] __k…