From: Sean Christopherson Date: Wed, 22 Mar 2023 16:55:20 +0000 (-0700) Subject: KVM: SVM: Fix benign "bool vs. int" comparison in svm_set_cr0() X-Git-Tag: v6.4-rc1~60^2~5^2~9 X-Git-Url: https://repo.jachan.dev/linux.git/commitdiff_plain/0c928ff26bd6 KVM: SVM: Fix benign "bool vs. int" comparison in svm_set_cr0() Explicitly convert the return from is_paging() to a bool when comparing against old_paging, which is also a boolean. is_paging() sneakily uses kvm_read_cr0_bits() and returns an int, i.e. returns X86_CR0_PG or 0, not 1 or 0. Luckily, the bug is benign as it only results in a false positive, not a false negative, i.e. only causes a spurious refresh of CR4 when paging is enabled in both the old and new. Cc: Maxim Levitsky Fixes: c53bbe2145f5 ("KVM: x86: SVM: don't passthrough SMAP/SMEP/PKE bits in !NPT && !gCR0.PG case") Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 70183d2271b5..19794a8ea28c 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1802,7 +1802,7 @@ void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) if (!npt_enabled) { hcr0 |= X86_CR0_PG | X86_CR0_WP; - if (old_paging != is_paging(vcpu)) + if (old_paging != !!is_paging(vcpu)) svm_set_cr4(vcpu, kvm_read_cr4(vcpu)); }