From: Claudio Imbrenda Date: Mon, 3 Aug 2026 12:40:30 +0000 (+0200) Subject: KVM: s390: Fix kvm_s390_vcpu_unsetup_cmma() X-Git-Tag: v7.2-rc7~19^2~2^2~10 X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=b050f741fd0d636f2daab72b74aeccea97abdb5f;p=thirdparty%2Fkernel%2Flinux.git KVM: s390: Fix kvm_s390_vcpu_unsetup_cmma() In some cases kvm_s390_vcpu_unsetup_cmma() can be called with a 0 cbrlo; in such cases, if running with V != R, free_page() will attempt to free physical page 0. Fix by freeing cbrlo only if it's non-zero. Fixes: b31605c12f4e ("KVM: s390: make cmma usage conditionally") Fixes: 29b40f105ec8 ("KVM: s390: protvirt: Add initial vm and cpu lifecycle handling") Signed-off-by: Claudio Imbrenda Message-ID: <20260803124040.126471-4-imbrenda@linux.ibm.com> --- diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 1b3290a5ad1a..9be27db0a21e 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3678,7 +3678,8 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu) void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu) { - free_page((unsigned long)phys_to_virt(vcpu->arch.sie_block->cbrlo)); + if (vcpu->arch.sie_block->cbrlo) + free_page((unsigned long)phys_to_virt(vcpu->arch.sie_block->cbrlo)); vcpu->arch.sie_block->cbrlo = 0; }