From: Wei Liu <wei.liu@kernel.org>
To: Yi Xie <xieyi@kylinos.cn>,
ssengar@microsoft.com, namjain@linux.microsoft.com
Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
decui@microsoft.com, longli@microsoft.com,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mshv: bounds-check cpu index in vtl mmap fault handler
Date: Wed, 22 Jul 2026 15:22:42 -0700 [thread overview]
Message-ID: <20260722222242.GF2020652@liuwe-devbox-debian-v2.local> (raw)
In-Reply-To: <20260709021947.49436-1-xieyi@kylinos.cn>
Naman, Saurabh, please review this.
On Thu, Jul 09, 2026 at 10:19:47AM +0800, Yi Xie wrote:
> cpu is taken from pgoff & 0xffff. cpu_online() does not reject cpu >=
> nr_cpu_ids, and per_cpu_ptr() can then walk off __per_cpu_offset.
>
> Signed-off-by: Yi Xie <xieyi@kylinos.cn>
> ---
> drivers/hv/mshv_vtl_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hv/mshv_vtl_main.c b/drivers/hv/mshv_vtl_main.c
> index 0d3d4161974f..fc50c44ac1bd 100644
> --- a/drivers/hv/mshv_vtl_main.c
> +++ b/drivers/hv/mshv_vtl_main.c
> @@ -801,7 +801,7 @@ static vm_fault_t mshv_vtl_fault(struct vm_fault *vmf)
> int cpu = vmf->pgoff & MSHV_PG_OFF_CPU_MASK;
> int real_off = vmf->pgoff >> MSHV_REAL_OFF_SHIFT;
>
> - if (!cpu_online(cpu))
> + if (cpu >= nr_cpu_ids || !cpu_online(cpu))
> return VM_FAULT_SIGBUS;
> /*
> * CPU Hotplug is not supported in VTL2 in OpenHCL, where this kernel driver exists.
> --
> 2.34.1
prev parent reply other threads:[~2026-07-22 22:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-09 2:19 [PATCH] mshv: bounds-check cpu index in vtl mmap fault handler Yi Xie
2026-07-09 2:51 ` sashiko-bot
2026-07-22 22:22 ` Wei Liu [this message]
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