Re: [Xen-devel] [PATCH] tools/ocaml: oxenstored: correctly handle a full ring.

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

You'll do :-P

On Fri, 2013-02-15 at 09:02 +0000, Keir Fraser wrote:
> Who are you looking for an Ack from? The patch makes pefect sense to me so
> you can have mine if you want it.
> 
> Acked-by: Keir Fraser <keir@xxxxxxx>
> 
> 
> On 15/02/2013 08:41, "Ian Campbell" <Ian.Campbell@xxxxxxxxxx> wrote:
> 
> > Can I get an ACK or NACK for this please, we really should update XSA-38
> > ASAP...
> > 
> > On Wed, 2013-02-13 at 09:43 +0000, Ian Campbell wrote:
> >> Change 26521:2c0fd406f02c (part of XSA-38 / CVE-2013-0215) incorrectly
> >> caused us to ignore rather than process a completely full ring. Check if
> >> producer and consumer are equal before masking to avoid this, since prod ==
> >> cons + PAGE_SIZE after masking becomes prod == cons.
> >> 
> >> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> >> ---
> >>  tools/ocaml/libs/xb/xs_ring_stubs.c |    4 ++--
> >>  1 files changed, 2 insertions(+), 2 deletions(-)
> >> 
> >> diff --git a/tools/ocaml/libs/xb/xs_ring_stubs.c
> >> b/tools/ocaml/libs/xb/xs_ring_stubs.c
> >> index 4888ac5..fdd9983 100644
> >> --- a/tools/ocaml/libs/xb/xs_ring_stubs.c
> >> +++ b/tools/ocaml/libs/xb/xs_ring_stubs.c
> >> @@ -45,10 +45,10 @@ static int xs_ring_read(struct mmap_interface 
> >> *interface,
> >> cons = *(volatile uint32*)&intf->req_cons;
> >> prod = *(volatile uint32*)&intf->req_prod;
> >> xen_mb();
> >> - cons = MASK_XENSTORE_IDX(cons);
> >> - prod = MASK_XENSTORE_IDX(prod);
> >> if (prod == cons)
> >> return 0;
> >> + cons = MASK_XENSTORE_IDX(cons);
> >> + prod = MASK_XENSTORE_IDX(prod);
> >> if (prod > cons)
> >> to_read = prod - cons;
> >> else
> > 
> > 
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxx
> > http://lists.xen.org/xen-devel
> 
> 



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