From: Bibo Mao <maobibo@loongson.cn>
To: Huacai Chen <chenhuacai@kernel.org>
Cc: Huacai Chen <chenhuacai@loongson.cn>,
Paolo Bonzini <pbonzini@redhat.com>,
Tianrui Zhao <zhaotianrui@loongson.cn>,
kvm@vger.kernel.org, loongarch@lists.linux.dev,
linux-kernel@vger.kernel.org, Xuerui Wang <kernel@xen0n.name>,
Jiaxun Yang <jiaxun.yang@flygoat.com>,
stable@vger.kernel.org, Aurelien Jarno <aurel32@debian.org>
Subject: Re: [PATCH 1/2] LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
Date: Mon, 23 Mar 2026 15:56:00 +0800 [thread overview]
Message-ID: <696c5177-4a89-f0d0-c305-c1581e72aa3d@loongson.cn> (raw)
In-Reply-To: <CAAhV-H7rFtju3k=NYkAy6-O7f8U=CTNiryu2_Kr57pScjeH-yQ@mail.gmail.com>
On 2026/3/23 下午3:08, Huacai Chen wrote:
> On Mon, Mar 23, 2026 at 11:16 AM Bibo Mao <maobibo@loongson.cn> wrote:
>>
>>
>>
>> On 2026/3/22 下午9:53, Huacai Chen wrote:
>>> kvm_get_vcpu_by_cpuid() takes a cpuid parameter whose type is int, so
>>> cpuid can be negative. Let kvm_get_vcpu_by_cpuid() return NULL for this
>>> case so as to make it more robust.
>>>
>>> This fix an out-of-bounds access to kvm_arch::phyid_map::phys_map[].
>>>
>>> Cc: <stable@vger.kernel.org>
>>> Fixes: 73516e9da512adc ("LoongArch: KVM: Add vcpu mapping from physical cpuid")
>>> Reported-by: Aurelien Jarno <aurel32@debian.org>
>>> Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1131431
>>> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
>>> ---
>>> arch/loongarch/kvm/vcpu.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>> diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
>>> index 8ffd50a470e6..831f381a8fd1 100644
>>> --- a/arch/loongarch/kvm/vcpu.c
>>> +++ b/arch/loongarch/kvm/vcpu.c
>>> @@ -588,6 +588,9 @@ struct kvm_vcpu *kvm_get_vcpu_by_cpuid(struct kvm *kvm, int cpuid)
>>> {
>>> struct kvm_phyid_map *map;
>>>
>>> + if (cpuid < 0)
>>> + return NULL;
>>> +
>>> if (cpuid >= KVM_MAX_PHYID)
>>> return NULL;
>>>
>>>
>>
>> if (cpuid < 0 || cpuid >= KVM_MAX_PHYID)?
>> however both are OK for me.
> I use a similar style as kvm_get_vcpu_by_id(). :)
>
> But there is another warning which can't be solved by this series (and
> I doubt whether it can be solved unless revert 01a8e68396a6d51f5b).
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1131431
what is the kernel config file with bug
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1131431
kvm_eiointc_regs_access() seems has problem, it need convert to void *
before arithmetic operation. I do not know whether this patch can solve
this bug.
diff --git a/arch/loongarch/kvm/intc/eiointc.c
b/arch/loongarch/kvm/intc/eiointc.c
index d2acb4d09e73..71bd67b57338 100644
--- a/arch/loongarch/kvm/intc/eiointc.c
+++ b/arch/loongarch/kvm/intc/eiointc.c
@@ -472,34 +472,34 @@ static int kvm_eiointc_regs_access(struct
kvm_device *dev,
switch (addr) {
case EIOINTC_NODETYPE_START ... EIOINTC_NODETYPE_END:
offset = (addr - EIOINTC_NODETYPE_START) / 4;
- p = s->nodetype + offset * 4;
+ p = (void *)s->nodetype + offset * 4;
break;
case EIOINTC_IPMAP_START ... EIOINTC_IPMAP_END:
offset = (addr - EIOINTC_IPMAP_START) / 4;
- p = &s->ipmap + offset * 4;
+ p = (void *)&s->ipmap + offset * 4;
break;
case EIOINTC_ENABLE_START ... EIOINTC_ENABLE_END:
offset = (addr - EIOINTC_ENABLE_START) / 4;
- p = s->enable + offset * 4;
+ p = (void *)s->enable + offset * 4;
break;
case EIOINTC_BOUNCE_START ... EIOINTC_BOUNCE_END:
offset = (addr - EIOINTC_BOUNCE_START) / 4;
- p = s->bounce + offset * 4;
+ p = (void *)s->bounce + offset * 4;
break;
case EIOINTC_ISR_START ... EIOINTC_ISR_END:
offset = (addr - EIOINTC_ISR_START) / 4;
- p = s->isr + offset * 4;
+ p = (void *)s->isr + offset * 4;
break;
case EIOINTC_COREISR_START ... EIOINTC_COREISR_END:
if (cpu >= s->num_cpu)
return -EINVAL;
offset = (addr - EIOINTC_COREISR_START) / 4;
- p = s->coreisr[cpu] + offset * 4;
+ p = (void *)s->coreisr[cpu] + offset * 4;
break;
case EIOINTC_COREMAP_START ... EIOINTC_COREMAP_END:
offset = (addr - EIOINTC_COREMAP_START) / 4;
- p = s->coremap + offset * 4;
+ p = (void *)s->coremap + offset * 4;
break;
default:
kvm_err("%s: unknown eiointc register, addr = %d\n",
__func__, addr);
Regards
Bibo Mao
>
> Huacai
>
>>
>> Reviewed-by: Bibo Mao <maobibo@loongson.cn>
>>
next prev parent reply other threads:[~2026-03-23 7:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-22 13:53 [PATCH 1/2] LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust Huacai Chen
2026-03-22 13:53 ` [PATCH 2/2] LoongArch: KVM: Handle the case that EIOINTC's coremap is empty Huacai Chen
2026-03-23 3:14 ` Bibo Mao
2026-03-23 3:13 ` [PATCH 1/2] LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust Bibo Mao
2026-03-23 7:08 ` Huacai Chen
2026-03-23 7:56 ` Bibo Mao [this message]
2026-03-23 8:08 ` Bibo Mao
2026-03-23 8:14 ` Huacai Chen
2026-03-23 9:40 ` Bibo Mao
2026-03-23 18:36 ` Aurelien Jarno
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