Commit 79aaeec7 authored Jun 17, 2020 by Steven Price Committed by Greg Kroah-Hartman Jul 16, 2020

KVM: arm64: Fix kvm_reset_vcpu() return code being incorrect with SVE



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: 9a3cdf26 ("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


Signed-off-by: Sasha Levin <sashal@kernel.org>

parent a494529a

arch/arm64/kvm/reset.c

+7 −3

Original line number	Diff line number	Diff line
		@@ -258,7 +258,7 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
		int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
		{
		const struct kvm_regs *cpu_reset;
		int ret = -EINVAL;
		int ret;
		bool loaded;

		/* Reset PMU outside of the non-preemptible section */
		@@ -281,15 +281,19 @@ 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 (!cpu_has_32bit_el1())
		if (!cpu_has_32bit_el1()) {
		ret = -EINVAL;
		goto out;
		}
		cpu_reset = &default_regs_reset32;
		} else {
		cpu_reset = &default_regs_reset;