Re: [PATCH] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read
From: Eric Auger <eric.auger@redhat.com>
Date: 2021-06-21 12:21:57
Also in:
kvmarm, lkml
Hi, On 6/21/21 2:18 PM, Eric Auger wrote:
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: <redacted> # v4.19
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reported-by: Gavin Shan <redacted>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210412150034.29185-1-eric.auger@redhat.com (local)Maybe I should I prefixed the patch with [stable-4.19]. This is already on master and in various stable but did not apply on 4.19 Thanks Eric
quoted hunk ↗ jump to hunk
--- 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 6ada2432e37c..71d92096776e 100644 --- a/virt/kvm/arm/vgic/vgic-kvm-device.c +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c@@ -95,8 +95,8 @@ 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