Re: [Xen-devel] Invalid VA => ptr conversion with xc_dom_* API after XSA-55 fox

["Jan Beulich" <JBeulich%suse.com@localhost>]

>>> On 20.11.13 at 13:56, "Jean-Yves Migeon (NetBSD)" 
>>> <jym%NetBSD.org@localhost> wrote:
> Jeff and FastIce pointed out a regression between Xen 4.1.2 and 4.1.6 
> when starting NetBSD domU; the kernel syms table gets slightly corrupted 
> [1].
> 
> After dwelling into libxc code, FastIce noticed that changing back the 
> return value to "ptr + offset" (instead of just "ptr") for 
> xc_dom_vaddr_to_ptr() makes it work again.
> 
> According to [2] while fixing XSA-55, Ian changed the "ptr + offset" 
> return value to just "ptr". Is there a reason for this? IMHO the VA => 
> ptr conversion should also take into account non-page aligned addresses, 
> hence the offset (except for NULL value of course).

I agree, but let's see what Ian (being the author of the whole
patch set) says.

Jan