When reading the base address of the a REDIST region through KVM_VGIC_V3_ADDR_TYPE_REDIST we expect the redistributor region list to be populated with a single element.

However list_first_entry() expects the list to be non empty. Instead we should use list_first_entry_or_null which effectively returns NULL if the list is empty.

Fixes: dbd9733ab674 ("KVM: arm/arm64: Replace the single rdist region by a list") Cc: Stable@vger.kernel.org # v5.4 Signed-off-by: Eric Auger eric.auger@redhat.com Reported-by: Gavin Shan gshan@redhat.com Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20210412150034.29185-1-eric.auger@redhat.com --- virt/kvm/arm/vgic/vgic-kvm-device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c index 44419679f91a..5eaede3e3b5a 100644 --- a/virt/kvm/arm/vgic/vgic-kvm-device.c +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c @@ -87,8 +87,8 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write) r = vgic_v3_set_redist_base(kvm, 0, *addr, 0); goto out; } - rdreg = list_first_entry(&vgic->rd_regions, - struct vgic_redist_region, list); + rdreg = list_first_entry_or_null(&vgic->rd_regions, + struct vgic_redist_region, list); if (!rdreg) addr_ptr = &undef_value; else