[ovs-dev] odp-util: Don't attempt to write IPv6 flow label bits that don't exist.

Message ID 20180906224206.17074-1-blp@ovn.org
State Accepted
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Series
  • [ovs-dev] odp-util: Don't attempt to write IPv6 flow label bits that don't exist.
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Commit Message

Ben Pfaff Sept. 6, 2018, 10:42 p.m.
The ipv6_label field member of struct ovs_key_ipv6 is 32 bits in size,
but an IPv6 label is only 20 bits, so the upper 12 bits are not writable
and must be 0 in the mask.  The code wasn't careful about this so it could
try to write them anyway.  This commit fixes the problem.

Reported-by: nm_r@directbox.com
Reported-at: https://mail.openvswitch.org/pipermail/ovs-discuss/2018-September/047357.html
Signed-off-by: Ben Pfaff <blp@ovn.org>
---
 lib/odp-util.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Yifeng Sun Sept. 12, 2018, 7:33 p.m. | #1
Upper 12 bits are zeroed out. Looks good to me, thanks.

Reviewed-by: Yifeng Sun <pkusunyifeng@gmail.com>

On Thu, Sep 6, 2018 at 3:42 PM Ben Pfaff <blp@ovn.org> wrote:

> The ipv6_label field member of struct ovs_key_ipv6 is 32 bits in size,
> but an IPv6 label is only 20 bits, so the upper 12 bits are not writable
> and must be 0 in the mask.  The code wasn't careful about this so it could
> try to write them anyway.  This commit fixes the problem.
>
> Reported-by: nm_r@directbox.com
> Reported-at:
> https://mail.openvswitch.org/pipermail/ovs-discuss/2018-September/047357.html
> Signed-off-by: Ben Pfaff <blp@ovn.org>
> ---
>  lib/odp-util.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/lib/odp-util.c b/lib/odp-util.c
> index cf62550bfec2..890c71b7f336 100644
> --- a/lib/odp-util.c
> +++ b/lib/odp-util.c
> @@ -7260,6 +7260,7 @@ commit_set_ipv6_action(const struct flow *flow,
> struct flow *base_flow,
>      get_ipv6_key(&wc->masks, &mask, true);
>      mask.ipv6_proto = 0;        /* Not writeable. */
>      mask.ipv6_frag = 0;         /* Not writable. */
> +    mask.ipv6_label &= htonl(IPV6_LABEL_MASK); /* Not writable. */
>
>      if (flow_tnl_dst_is_set(&base_flow->tunnel) &&
>          ((base_flow->nw_tos ^ flow->nw_tos) & IP_ECN_MASK) == 0) {
> --
> 2.16.1
>
> _______________________________________________
> dev mailing list
> dev@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>
Ben Pfaff Sept. 12, 2018, 9:29 p.m. | #2
Thanks.  Applied to master and backported as far as branch-2.4.

On Wed, Sep 12, 2018 at 12:33:39PM -0700, Yifeng Sun wrote:
> Upper 12 bits are zeroed out. Looks good to me, thanks.
> 
> Reviewed-by: Yifeng Sun <pkusunyifeng@gmail.com>
> 
> On Thu, Sep 6, 2018 at 3:42 PM Ben Pfaff <blp@ovn.org> wrote:
> 
> > The ipv6_label field member of struct ovs_key_ipv6 is 32 bits in size,
> > but an IPv6 label is only 20 bits, so the upper 12 bits are not writable
> > and must be 0 in the mask.  The code wasn't careful about this so it could
> > try to write them anyway.  This commit fixes the problem.
> >
> > Reported-by: nm_r@directbox.com
> > Reported-at:
> > https://mail.openvswitch.org/pipermail/ovs-discuss/2018-September/047357.html
> > Signed-off-by: Ben Pfaff <blp@ovn.org>
> > ---
> >  lib/odp-util.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/lib/odp-util.c b/lib/odp-util.c
> > index cf62550bfec2..890c71b7f336 100644
> > --- a/lib/odp-util.c
> > +++ b/lib/odp-util.c
> > @@ -7260,6 +7260,7 @@ commit_set_ipv6_action(const struct flow *flow,
> > struct flow *base_flow,
> >      get_ipv6_key(&wc->masks, &mask, true);
> >      mask.ipv6_proto = 0;        /* Not writeable. */
> >      mask.ipv6_frag = 0;         /* Not writable. */
> > +    mask.ipv6_label &= htonl(IPV6_LABEL_MASK); /* Not writable. */
> >
> >      if (flow_tnl_dst_is_set(&base_flow->tunnel) &&
> >          ((base_flow->nw_tos ^ flow->nw_tos) & IP_ECN_MASK) == 0) {
> > --
> > 2.16.1
> >
> > _______________________________________________
> > dev mailing list
> > dev@openvswitch.org
> > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
> >

Patch

diff --git a/lib/odp-util.c b/lib/odp-util.c
index cf62550bfec2..890c71b7f336 100644
--- a/lib/odp-util.c
+++ b/lib/odp-util.c
@@ -7260,6 +7260,7 @@  commit_set_ipv6_action(const struct flow *flow, struct flow *base_flow,
     get_ipv6_key(&wc->masks, &mask, true);
     mask.ipv6_proto = 0;        /* Not writeable. */
     mask.ipv6_frag = 0;         /* Not writable. */
+    mask.ipv6_label &= htonl(IPV6_LABEL_MASK); /* Not writable. */
 
     if (flow_tnl_dst_is_set(&base_flow->tunnel) &&
         ((base_flow->nw_tos ^ flow->nw_tos) & IP_ECN_MASK) == 0) {