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
next 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
2026-07-22 22:22 ` Wei Liu [this message]
2026-07-23 9:07 ` Naman Jain
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260722222242.GF2020652@liuwe-devbox-debian-v2.local \
--to=wei.liu@kernel.org \
--cc=decui@microsoft.com \
--cc=haiyangz@microsoft.com \
--cc=kys@microsoft.com \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=longli@microsoft.com \
--cc=namjain@linux.microsoft.com \
--cc=ssengar@microsoft.com \
--cc=xieyi@kylinos.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox