From: Schspa Shi <schspa@gmail.com>
To: Marc Zyngier <maz@kernel.org>
Cc: james.morse@arm.com, alexandru.elisei@arm.com,
suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: arm64: Fix 64 bit mmio handle
Date: Fri, 01 Jul 2022 22:22:51 +0800 [thread overview]
Message-ID: <m2h740zz1i.fsf@gmail.com> (raw)
In-Reply-To: <87letd0wqm.wl-maz@kernel.org>
Marc Zyngier <maz@kernel.org> writes:
>>
>> I have running some static code analysis software upon Kernel
>> code.
>> Seeing there is possible overflow.
>>
>> maks << 1U << ((len * 8) -1);
>>
>> The AI don't know, len is only the value of 1, 2, 4, and make
>> this
>> a warnings
>>
>> I tring to analysis this, but didn't realize the real scenario
>> of
>> sign extension, and finally sent this problematic patch.
>>
>> I do see some uninitialized memory reads (the values are not
>> used
>> in the end, just as temporary space for API execution),
>> do we need to fix these?
>
> You need to be more descriptive here. What uninitialised reads?
> In
> general, pointing at the code and providing a full description
> of what
> you think is incorrect would really help...
>
> M.
One example is
int vgic_v3_has_attr_regs(struct kvm_device *dev, struct
kvm_device_attr *attr)
{
...
case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS: {
u64 reg, id;
id = (attr->attr & KVM_DEV_ARM_VGIC_SYSREG_INSTR_MASK);
return vgic_v3_has_cpu_sysregs_attr(vcpu, 0, id, ®);
}
}
The funcion vgic_v3_has_cpu_sysregs_attr will read reg's value to
params without initialization. There should have no problems,
because the register value never used.
--
BRs
Schspa Shi
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next prev parent reply other threads:[~2022-07-01 14:31 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-30 16:12 [PATCH] KVM: arm64: Fix 64 bit mmio handle Schspa Shi
2022-06-30 16:23 ` Marc Zyngier
2022-06-30 16:50 ` Schspa Shi
2022-07-01 10:50 ` Marc Zyngier
2022-07-01 12:22 ` Schspa Shi
2022-07-01 13:48 ` Marc Zyngier
2022-07-01 14:22 ` Schspa Shi [this message]
2022-07-06 7:11 ` Marc Zyngier
2022-07-06 11:29 ` Schspa Shi
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