* [PATCH] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read
@ 2021-04-12 15:00 Eric Auger
2021-04-13 6:05 ` Keqian Zhu
2021-04-13 14:05 ` Marc Zyngier
0 siblings, 2 replies; 3+ messages in thread
From: Eric Auger @ 2021-04-12 15:00 UTC (permalink / raw)
To: eric.auger.pro, eric.auger, linux-kernel, kvm, kvmarm, maz,
alexandru.elisei, suzuki.poulose, james.morse
Cc: drjones, gshan
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>
---
arch/arm64/kvm/vgic/vgic-kvm-device.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index 44419679f91a..5eaede3e3b5a 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
--
2.26.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read
2021-04-12 15:00 [PATCH] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read Eric Auger
@ 2021-04-13 6:05 ` Keqian Zhu
2021-04-13 14:05 ` Marc Zyngier
1 sibling, 0 replies; 3+ messages in thread
From: Keqian Zhu @ 2021-04-13 6:05 UTC (permalink / raw)
To: Eric Auger, eric.auger.pro, linux-kernel, kvm, kvmarm, maz,
alexandru.elisei, suzuki.poulose, james.morse
Cc: drjones, gshan
On 2021/4/12 23:00, 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.
Indeed, list_first_entry() always return a non-null ptr. If the list
is empty, it will mistake the list head as the first element.
> 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>
> ---
> arch/arm64/kvm/vgic/vgic-kvm-device.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
> index 44419679f91a..5eaede3e3b5a 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
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read
2021-04-12 15:00 [PATCH] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read Eric Auger
2021-04-13 6:05 ` Keqian Zhu
@ 2021-04-13 14:05 ` Marc Zyngier
1 sibling, 0 replies; 3+ messages in thread
From: Marc Zyngier @ 2021-04-13 14:05 UTC (permalink / raw)
To: james.morse, eric.auger.pro, kvmarm, linux-kernel,
alexandru.elisei, kvm, Eric Auger, suzuki.poulose
Cc: gshan, drjones
On Mon, 12 Apr 2021 17:00:34 +0200, 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.
Applied to kvm-arm64/vgic-5.13, thanks!
[1/1] KVM: arm/arm64: Fix KVM_VGIC_V3_ADDR_TYPE_REDIST read
commit: 94ac0835391efc1a30feda6fc908913ec012951e
Cheers,
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-04-13 6:05 ` Keqian Zhu
2021-04-13 14:05 ` Marc Zyngier
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