Commit b2bc9494 authored by Marc Zyngier's avatar Marc Zyngier Committed by openeuler-sync-bot
Browse files

KVM: arm64: vgic-v2: Use cpuid from userspace as vcpu_id 

stable inclusion
from stable-v5.10.217
commit 4563a0afd99e1d86acb7d54a0809ed27d273a7f6
category: cleanup
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9UOQA
CVE: CVE-2024-36953

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4563a0afd99e1d86acb7d54a0809ed27d273a7f6



--------------------------------

[ Upstream commit 4e7728c81a54b17bd33be402ac140bc11bb0c4f4 ]

When parsing a GICv2 attribute that contains a cpuid, handle this
as the vcpu_id, not a vcpu_idx, as userspace cannot really know
the mapping between the two. For this, use kvm_get_vcpu_by_id()
instead of kvm_get_vcpu().

Take this opportunity to get rid of the pointless check against
online_vcpus, which doesn't make much sense either, and switch
to FIELD_GET as a way to extract the vcpu_id.

Reviewed-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230927090911.3355209-5-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
Stable-dep-of: 6ddb4f372fc6 ("KVM: arm64: vgic-v2: Check for non-NULL vCPU in vgic_v2_parse_attr()")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarLiu Shixin <liushixin2@huawei.com>
(cherry picked from commit 466d01de)
parent dfdb6e44

arch/arm64/kvm/vgic/vgic-kvm-device.c

+2 −6
Original line number Diff line number Diff line
@@ -286,13 +286,9 @@ int vgic_v2_parse_attr(struct kvm_device *dev, struct kvm_device_attr *attr, 
{

	int cpuid;



	cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>

		 KVM_DEV_ARM_VGIC_CPUID_SHIFT;

	cpuid = FIELD_GET(KVM_DEV_ARM_VGIC_CPUID_MASK, attr->attr);



	if (cpuid >= atomic_read(&dev->kvm->online_vcpus))

		return -EINVAL;



	reg_attr->vcpu = kvm_get_vcpu(dev->kvm, cpuid);

	reg_attr->vcpu = kvm_get_vcpu_by_id(dev->kvm, cpuid);

	reg_attr->addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;



	return 0;