[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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

  • To: Jan Beulich <jbeulich@xxxxxxxx>
  • From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
  • Date: Fri, 29 Jan 2021 10:04:26 +0000
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=DoWaDJbl9ilQlfrl8FllvZ/vxseNaUYfNqf+cHQPzrs=; b=fHPmShcyMsI2QlCgg+17z9ekvq05OCJTg3/+jL/lVA5aC1afrspchVGryB0ZHzPWGD5/Z60I0eYeSfdIpKJpKxnfLv1EaCrxhyUQunsqTyRKBgGtomsBxB6DAJB6znSjfwtyenxNi5vQumevGR/QN/1S/i74QtJdaMdbvOi3nJ/lkU7W/KNUMYCGmoAZJpwOrmJTYXXAaBWdJzO6jrois46RRyXFrdK7HWhsJ7s0h0MJuo/0ZCATBOioyFdltptpjNVnIvnqf0Xna6QxccmHorA6Kpl/x0GywIro4uO56W+nSCh6G0/bZhm9ThOZGGc+GShLioZTslLTLg9FA5TgNQ==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=jWYbt/78IWHMFrNxjBj2I65Us9Z0LLr2tEJwhwkj1CXJU8Kb5BL7D6x+v6Z5cD1uHWO//kmsi92TDrz64SbAjGySHCrEmCVzc+JgBjZBlxYQXGxw4x8lBRsJ+aQ09l7nidne8pj9SWakFaVyfdSjRlbubeGXImR1QYYlNdGSJv5v6rHLhUb3SYsTV/c/tfJ1OTh8HQPR+SaI0fdoYcocUXK3Ei5JyHkYv9o+8lKj1uT/kYkH9H7bnNSu6MNGjr8qT3GkVNgFYBDU4KMWF2LZT7dRVk8i/YwgX93R4pLnuVB6OSyYCPCk8kIk+RRqR8N0YB2IUNcO9qAVBziGXuyH0g==
  • Authentication-results: esa5.hc3370-68.iphmx.com; dkim=pass (signature verified) header.i=@citrix.onmicrosoft.com
  • Cc: Roger Pau Monné <roger.pau@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>, Paul Durrant <paul@xxxxxxx>, Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • Delivery-date: Fri, 29 Jan 2021 10:04:43 +0000
  • Ironport-sdr: q6xA8U7YFDF2+LUeaFoTqH94PclNjoxzFnjIh7jhEexkfVOXHl15YlsDW/p/hNgvHtQ1xSGlCK 5ayqpGji1mJQup9Ws/RAnM7EUIdJR+Zg5yS8QzQlHS4eW6Rn0jilreR8PspiLXjbhn6iDawa4L /WFrgOij32nIf/1XUmBxbToMnavz0RM/3jg6p2ZNkC0+NzUI5DAhKrj44GZtqhg4OW7XmoEbOo 1+bQdhgtbSXeIVB1otlJmYMK817lcRZ8aNvHX6JwtLpltirutrGVUX2l36zVXNT6m2uN9iXGRn chs=
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

On 29/01/2021 10:01, Jan Beulich wrote:
> On 29.01.2021 10:47, Andrew Cooper wrote:
>> On 29/01/2021 09:40, Jan Beulich wrote:
>>> On 29.01.2021 10:32, Andrew Cooper wrote:
>>>> 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.
>> This specific patch fixes a real bug on arm32 which will cause unsigned
>> long + unsigned int to truncate together and permit certain values.
> Why Arm32 only? Looking at current staging, there's no overflow
> check at all on the grant part of the path. A suitably large
> 64-bit "frame" will allow the same behavior on 64-bit (wrapping
> around through zero), afaict.

Very good point.  I'd worked the logic through logically at the end of
my fixes, rather than at its position in the beginning of the series.

In which case I'll propagate through the whole call-tree.




Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.