From: Steven Price <steven.price@arm.com>
To: Dan Carpenter <dan.carpenter@linaro.org>,
Andre Przywara <andre.przywara@arm.com>
Cc: Oliver Upton <oliver.upton@linux.dev>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Eric Auger <eric.auger@redhat.com>,
linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH v2] KVM: arm64: Fix buffer overflow in kvm_arm_set_fw_reg()
Date: Wed, 19 Apr 2023 11:17:51 +0100 [thread overview]
Message-ID: <5ab50a0f-fb75-7435-4b59-98adcc223dfd@arm.com> (raw)
In-Reply-To: <4efbab8c-640f-43b2-8ac6-6d68e08280fe@kili.mountain>
On 19/04/2023 11:16, Dan Carpenter wrote:
> The KVM_REG_SIZE() comes from the ioctl and it can be a power of two
> between 0-32768 but if it is more than sizeof(long) this will corrupt
> memory.
>
> Fixes: 99adb567632b ("KVM: arm/arm64: Add save/restore support for firmware workaround state")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Thanks,
Steve
> ---
> v2: The original patch was okay but checking for != sizeof(val) is
> stricter and more Obviously Correct[tm]. Return -ENOENT instead of
> -EINVAL in case future ioctls are added which take a different size.
>
> arch/arm64/kvm/hypercalls.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
> index 2e16fc7b31bf..7fb4df0456de 100644
> --- a/arch/arm64/kvm/hypercalls.c
> +++ b/arch/arm64/kvm/hypercalls.c
> @@ -544,6 +544,8 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> u64 val;
> int wa_level;
>
> + if (KVM_REG_SIZE(reg->id) != sizeof(val))
> + return -ENOENT;
> if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)))
> return -EFAULT;
>
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next prev parent reply other threads:[~2023-04-19 10:18 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-19 10:16 [PATCH v2] KVM: arm64: Fix buffer overflow in kvm_arm_set_fw_reg() Dan Carpenter
2023-04-19 10:17 ` Steven Price [this message]
2023-04-19 10:21 ` Eric Auger
2023-04-19 11:31 ` Marc Zyngier
2023-04-19 12:06 ` Dan Carpenter
2023-04-19 15:24 ` Oliver Upton
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