From: Eric Auger Date: Mon, 12 Apr 2021 15:00:34 +0000 (+0200) Subject: KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read X-Git-Tag: v5.11.21~493 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e5c8eeab17c84407729fcb530ee00c2374728738;p=thirdparty%2Fkernel%2Fstable.git KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read 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: # v4.18+ Signed-off-by: Eric Auger Reported-by: Gavin Shan Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210412150034.29185-1-eric.auger@redhat.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c index 44419679f91ad..5eaede3e3b5a5 100644 --- a/arch/arm64/kvm/vgic/vgic-kvm-device.c +++ b/arch/arm64/kvm/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