From a24f1d80fbcdbf8b2a7044a00fa12b3972b4c31c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 16 Mar 2026 15:36:40 -0400 Subject: KVM: arm64: Eagerly init vgic dist/redist on vgic creation [ Upstream commit ac6769c8f948dff33265c50e524aebf9aa6f1be0 ] 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kvm/vgic/vgic-init.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index 86c149537493..6ed01c7faa91 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -143,6 +143,21 @@ 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->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF; + + aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC; + pfr1 = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC; + + if (type == KVM_DEV_TYPE_ARM_VGIC_V2) { + kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF; + } else { + INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions); + aa64pfr0 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP); + pfr1 |= SYS_FIELD_PREP_ENUM(ID_PFR1_EL1, GIC, GICv3); + } + + 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); @@ -157,25 +172,10 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) vgic_cpu->private_irqs = NULL; } + kvm->arch.vgic.vgic_model = 0; 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; - pfr1 = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC; - - if (type == KVM_DEV_TYPE_ARM_VGIC_V2) { - kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF; - } else { - INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions); - aa64pfr0 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP); - pfr1 |= SYS_FIELD_PREP_ENUM(ID_PFR1_EL1, GIC, GICv3); - } - - kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, aa64pfr0); - kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, pfr1); - if (type == KVM_DEV_TYPE_ARM_VGIC_V3) kvm->arch.vgic.nassgicap = system_supports_direct_sgis(); -- cgit v1.2.3