Re: [PATCH] xen/memory: Reject out-of-range resource 'frame' values

From: Jan Beulich <jbeulich@suse.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
	"Stefano Stabellini" <sstabellini@kernel.org>,
	"Julien Grall" <julien@xen.org>,
	"Volodymyr Babchuk" <Volodymyr_Babchuk@epam.com>,
	"Paul Durrant" <paul@xen.org>,
	"Oleksandr Tyshchenko" <oleksandr_tyshchenko@epam.com>,
	Xen-devel <xen-devel@lists.xenproject.org>
Subject: Re: [PATCH] xen/memory: Reject out-of-range resource 'frame' values
Date: Fri, 29 Jan 2021 10:40:29 +0100	[thread overview]
Message-ID: <73e7ec42-12be-5b03-7c91-14e3132d3324@suse.com> (raw)
In-Reply-To: <c31e3d04-6c01-95fd-af51-bbcbf0f450d3@citrix.com>

On 29.01.2021 10:32, Andrew Cooper wrote:
> On 29/01/2021 09:15, Jan Beulich wrote:
>> On 28.01.2021 17:06, Andrew Cooper wrote:
>>> --- a/xen/common/memory.c
>>> +++ b/xen/common/memory.c
>>> @@ -1054,7 +1054,7 @@ static long xatp_permission_check(struct domain *d, unsigned int space)
>>>  }
>>>  
>>>  static int acquire_grant_table(struct domain *d, unsigned int id,
>>> -                               unsigned long frame,
>>> +                               unsigned int frame,
>>>                                 unsigned int nr_frames,
>>>                                 xen_pfn_t mfn_list[])
>>>  {
>> Doesn't this want carrying forward into
>> gnttab_get_{shared,status}_frame() as well? Of course further
>> cleanup here can also be done at a later point, but it leaves
>> things in a somewhat inconsistent state. I'd like to leave it
>> up to you to commit with Paul's R-b as is, or extend the
>> adjustments and then also add mine.
> 
> In the series, those functions are deleted by the next patch.

In your submission you talk about a v8 series, which I took to
mean the vmtrace one. I understand here you refer to the other
series, presently at v3?

> What's the likelihood that you'll choose to backport this?

Didn't consider this aspect yet. I think I wouldn't have picked
it without anyone asking for it to be backported.

>  I can extend it if needs be.

Well, if that deletion of code gets committed in time, then of
course there's no real need to fiddle with it here.

Jan