6.6-stable review patch. If anyone has any objections, please let me know.
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From: Marc Zyngier maz@kernel.org
commit 0d92e4a7ffd5c42b9fa864692f82476c0bf8bcc8 upstream.
When tearing down a redistributor region, make sure we don't have any dangling pointer to that region stored in a vcpu.
Fixes: e5a35635464b ("kvm: arm64: vgic-v3: Introduce vgic_v3_free_redist_region()") Reported-by: Alexander Potapenko glider@google.com Reviewed-by: Oliver Upton oliver.upton@linux.dev Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20240605175637.1635653-1-maz@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kvm/vgic/vgic-init.c | 2 +- arch/arm64/kvm/vgic/vgic-mmio-v3.c | 15 +++++++++++++-- arch/arm64/kvm/vgic/vgic.h | 2 +- 3 files changed, 15 insertions(+), 4 deletions(-)
--- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -355,7 +355,7 @@ static void kvm_vgic_dist_destroy(struct
if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) { list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list) - vgic_v3_free_redist_region(rdreg); + vgic_v3_free_redist_region(kvm, rdreg); INIT_LIST_HEAD(&dist->rd_regions); } else { dist->vgic_cpu_base = VGIC_ADDR_UNDEF; --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c @@ -942,8 +942,19 @@ free: return ret; }
-void vgic_v3_free_redist_region(struct vgic_redist_region *rdreg) +void vgic_v3_free_redist_region(struct kvm *kvm, struct vgic_redist_region *rdreg) { + struct kvm_vcpu *vcpu; + unsigned long c; + + lockdep_assert_held(&kvm->arch.config_lock); + + /* Garbage collect the region */ + kvm_for_each_vcpu(c, vcpu, kvm) { + if (vcpu->arch.vgic_cpu.rdreg == rdreg) + vcpu->arch.vgic_cpu.rdreg = NULL; + } + list_del(&rdreg->list); kfree(rdreg); } @@ -968,7 +979,7 @@ int vgic_v3_set_redist_base(struct kvm *
mutex_lock(&kvm->arch.config_lock); rdreg = vgic_v3_rdist_region_from_index(kvm, index); - vgic_v3_free_redist_region(rdreg); + vgic_v3_free_redist_region(kvm, rdreg); mutex_unlock(&kvm->arch.config_lock); return ret; } --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -310,7 +310,7 @@ vgic_v3_rd_region_size(struct kvm *kvm,
struct vgic_redist_region *vgic_v3_rdist_region_from_index(struct kvm *kvm, u32 index); -void vgic_v3_free_redist_region(struct vgic_redist_region *rdreg); +void vgic_v3_free_redist_region(struct kvm *kvm, struct vgic_redist_region *rdreg);
bool vgic_v3_rdist_overlap(struct kvm *kvm, gpa_t base, size_t size);