From: Eric Auger eric.auger@redhat.com
commit 94ac0835391efc1a30feda6fc908913ec012951e upstream.
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 # v4.18+ 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- virt/kvm/arm/vgic/vgic-kvm-device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- 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, unsig 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