KVM: arm64: Fix kvm_reset_vcpu() return code being incorrect with SVE (66b7e05d) · Commits · 戴 / test

If SVE is enabled then 'ret' can be assigned the return value of kvm_vcpu_enable_sve() which may be 0 causing future "goto out" sites to erroneously return 0 on failure rather than -EINVAL as expected. Remove the initialisation of 'ret' and make setting the return value explicit to avoid this situation in the future. Fixes: ("KVM: arm64/sve: Allow userspace to enable SVE for vcpus") Cc: stable@vger.kernel.org Reported-by:

James Morse <james.morse@arm.com> Signed-off-by:

Steven Price <steven.price@arm.com> Signed-off-by:

Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200617105456.28245-1-steven.price@arm.com

arch/arm64/kvm/reset.c

+7 −3

Original line number	Diff line number	Diff line
		@@ -245,7 +245,7 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
		*/
		int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
		{
		int ret = -EINVAL;
		int ret;
		bool loaded;
		u32 pstate;

		@@ -269,15 +269,19 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)

		if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) \|\|
		test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) {
		if (kvm_vcpu_enable_ptrauth(vcpu))
		if (kvm_vcpu_enable_ptrauth(vcpu)) {
		ret = -EINVAL;
		goto out;
		}
		}

		switch (vcpu->arch.target) {
		default:
		if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
		if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1))
		if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) {
		ret = -EINVAL;
		goto out;
		}
		pstate = VCPU_RESET_PSTATE_SVC;
		} else {
		pstate = VCPU_RESET_PSTATE_EL1;

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