From ac6769c8f948dff33265c50e524aebf9aa6f1be0 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sat, 28 Feb 2026 16:45:59 +0000 Subject: [PATCH] KVM: arm64: Eagerly init vgic dist/redist on vgic creation If vgic_allocate_private_irqs_locked() fails for any odd reason, we exit kvm_vgic_create() early, leaving dist->rd_regions uninitialised. kvm_vgic_dist_destroy() then comes along and walks into the weeds trying to free the RDs. Got to love this stuff. Solve it by moving all the static initialisation early, and make sure that if we fail halfway, we're in a reasonable shape to perform the rest of the teardown. While at it, reset the vgic model on failure, just in case... Reported-by: syzbot+f6a46b038fc243ac0175@syzkaller.appspotmail.com Tested-by: syzbot+f6a46b038fc243ac0175@syzkaller.appspotmail.com Fixes: b3aa9283c0c50 ("KVM: arm64: vgic: Hoist SGI/PPI alloc from vgic_init() to kvm_create_vgic()") Link: https://lore.kernel.org/r/69a2d58c.050a0220.3a55be.003b.GAE@google.com Link: https://patch.msgid.link/20260228164559.936268-1-maz@kernel.org Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org --- arch/arm64/kvm/vgic/vgic-init.c | 34 ++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index 9b3091ad868c..e9b8b5fc480c 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -143,23 +143,6 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) kvm->arch.vgic.in_kernel = true; kvm->arch.vgic.vgic_model = type; kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST; - - kvm_for_each_vcpu(i, vcpu, kvm) { - ret = vgic_allocate_private_irqs_locked(vcpu, type); - if (ret) - break; - } - - if (ret) { - kvm_for_each_vcpu(i, vcpu, kvm) { - struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; - kfree(vgic_cpu->private_irqs); - vgic_cpu->private_irqs = NULL; - } - - goto out_unlock; - } - kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF; aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC; @@ -176,6 +159,23 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, aa64pfr0); kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, pfr1); + kvm_for_each_vcpu(i, vcpu, kvm) { + ret = vgic_allocate_private_irqs_locked(vcpu, type); + if (ret) + break; + } + + if (ret) { + kvm_for_each_vcpu(i, vcpu, kvm) { + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + kfree(vgic_cpu->private_irqs); + vgic_cpu->private_irqs = NULL; + } + + kvm->arch.vgic.vgic_model = 0; + goto out_unlock; + } + if (type == KVM_DEV_TYPE_ARM_VGIC_V3) kvm->arch.vgic.nassgicap = system_supports_direct_sgis();