Re: [PATCH v2] mshv_vtl: clear hypercall output before copyout

Wei Liu <[email protected]> Wed, 22 Jul 2026 15:07:01 -0700
Newsgroups org.kernel.vger.linux-hyperv,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On Thu, Jun 25, 2026 at 08:13:14PM +0200, Yousef Alhouseen wrote:
> mshv_vtl_hvcall_call() copies output_size bytes to userspace.
> 
> The output page is freshly allocated. Userspace chooses the copyout length.
> 
> If the hypercall writes less, the tail can contain stale page data.
> 
> Clear the copied range before issuing the hypercall.
> 
> Also check both bounce page allocations before either page is used.
> 
> Signed-off-by: Yousef Alhouseen <[email protected]>

Applied. Thanks.