Re: [PATCH 6.1] Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Oct 09, 2024 at 04:16:26PM +0800, Xiangyu Chen wrote:
> From: Rick Edgecombe <rick.p.edgecombe@intel.com>
> 
> In CoCo VMs it is possible for the untrusted host to cause
> set_memory_encrypted() or set_memory_decrypted() to fail such that an
> error is returned and the resulting memory is shared. Callers need to
> take care to handle these errors to avoid returning decrypted (shared)
> memory to the page allocator, which could lead to functional or security
> issues.
> 
> VMBus code could free decrypted pages if set_memory_encrypted()/decrypted()
> fails. Leak the pages if this happens.
> 
> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
> Signed-off-by: Michael Kelley <mhklinux@outlook.com>
> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Link: https://lore.kernel.org/r/20240311161558.1310-2-mhklinux@outlook.com
> Signed-off-by: Wei Liu <wei.liu@kernel.org>
> Message-ID: <20240311161558.1310-2-mhklinux@outlook.com>
> [Xiangyu: Modified to apply on 6.1.y]
> Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
> ---
>  drivers/hv/connection.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)

Are you sure?  This is _VERY_ different from what you suggested for
5.15.y and what is in mainline.  Also, you didn't show the git id for
the upstream commit.

Please work to figure this out and resend working versions for ALL
affected branches as new patches.

thanks,

greg k-h