If kvm_arch_vcpu_create() fails to share the vCPU page with the hypervisor, we propagate the error back to the ioctl but leave the vGIC vCPU data initialised. Note only does this leak the corresponding memory when the vCPU is destroyed but it can also lead to use-after-free if the redistributor device handling tries to walk into the vCPU.
Add the missing cleanup to kvm_arch_vcpu_create(), ensuring that the vGIC vCPU structures are destroyed on error.
Cc: stable@vger.kernel.org Cc: Marc Zyngier maz@kernel.org Cc: Oliver Upton oliver.upton@linux.dev Cc: Quentin Perret qperret@google.com Signed-off-by: Will Deacon will@kernel.org ---
It's hard to come up with a "Fixes:" tag for this. Prior to 3f868e142c0b ("KVM: arm64: Introduce kvm_share_hyp()"), create_hyp_mappings() could still have failed, although if you go back before 66c57edd3bc7 ("KVM: arm64: Restrict EL2 stage-1 changes in protected mode") then it's vanishingly unlikely.
arch/arm64/kvm/arm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index b8e55a441282..fa71cee02faa 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -466,7 +466,11 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) if (err) return err;
- return kvm_share_hyp(vcpu, vcpu + 1); + err = kvm_share_hyp(vcpu, vcpu + 1); + if (err) + kvm_vgic_vcpu_destroy(vcpu); + + return err; }
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
On Fri, 14 Mar 2025 13:34:09 +0000, Will Deacon will@kernel.org wrote:
If kvm_arch_vcpu_create() fails to share the vCPU page with the hypervisor, we propagate the error back to the ioctl but leave the vGIC vCPU data initialised. Note only does this leak the corresponding memory when the vCPU is destroyed but it can also lead to use-after-free if the redistributor device handling tries to walk into the vCPU.
Add the missing cleanup to kvm_arch_vcpu_create(), ensuring that the vGIC vCPU structures are destroyed on error.
Cc: stable@vger.kernel.org Cc: Marc Zyngier maz@kernel.org Cc: Oliver Upton oliver.upton@linux.dev Cc: Quentin Perret qperret@google.com Signed-off-by: Will Deacon will@kernel.org
It's hard to come up with a "Fixes:" tag for this. Prior to 3f868e142c0b ("KVM: arm64: Introduce kvm_share_hyp()"), create_hyp_mappings() could still have failed, although if you go back before 66c57edd3bc7 ("KVM: arm64: Restrict EL2 stage-1 changes in protected mode") then it's vanishingly unlikely.
arch/arm64/kvm/arm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index b8e55a441282..fa71cee02faa 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -466,7 +466,11 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) if (err) return err;
- return kvm_share_hyp(vcpu, vcpu + 1);
- err = kvm_share_hyp(vcpu, vcpu + 1);
- if (err)
kvm_vgic_vcpu_destroy(vcpu);- return err;
} void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
Reviewed-by: Marc Zyngier maz@kernel.org
M.
On Fri, 14 Mar 2025 13:34:09 +0000, Will Deacon wrote:
If kvm_arch_vcpu_create() fails to share the vCPU page with the hypervisor, we propagate the error back to the ioctl but leave the vGIC vCPU data initialised. Note only does this leak the corresponding memory when the vCPU is destroyed but it can also lead to use-after-free if the redistributor device handling tries to walk into the vCPU.
Add the missing cleanup to kvm_arch_vcpu_create(), ensuring that the vGIC vCPU structures are destroyed on error.
[...]
Applied to next, thanks!
[1/1] KVM: arm64: Tear down vGIC on failed vCPU creation https://git.kernel.org/kvmarm/kvmarm/c/250f25367b58
-- Best, Oliver
linux-stable-mirror@lists.linaro.org
-
Marc Zyngier -
Oliver Upton -
Will Deacon