| Message ID | 20200617105456.28245-1-steven.price@arm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 66b7e05dc0239c5817859f261098ba9cc2efbd2b |
| Headers | show |
| Series | [v2] KVM: arm64: kvm_reset_vcpu() return code incorrect with SVE | expand |
On Wed, 17 Jun 2020 11:54:56 +0100, Steven Price wrote: > 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. Applied to next, thanks! [1/1] KVM: arm64: Fix kvm_reset_vcpu() return code being incorrect with SVE commit: 66b7e05dc0239c5817859f261098ba9cc2efbd2b Cheers, M.
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index d3b209023727..6ed36be51b4b 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -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;
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: 9a3cdf26e336 ("KVM: arm64/sve: Allow userspace to enable SVE for vcpus") Reported-by: James Morse <james.morse@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> --- Changes since v1: * Fix embarrassing accidental inversion of the if() test The problematic chunk isn't visible in the diff, so reproduced here: if (!kvm_arm_vcpu_sve_finalized(vcpu)) { if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) { ret = kvm_vcpu_enable_sve(vcpu); if (ret) goto out; } } else { kvm_vcpu_reset_sve(vcpu); } arch/arm64/kvm/reset.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)