| Message ID | 01a8af8654b87058ecd421e471d760a43784ab96.1652456873.git.lucien.xin@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [ipsec] xfrm: set dst dev to blackhole_netdev instead of loopback_dev in ifdown | expand |
On Fri, May 13, 2022 at 8:47 AM Xin Long <lucien.xin@gmail.com> wrote: > > The global blackhole_netdev has replaced pernet loopback_dev to become the > one given to the object that holds an netdev when ifdown in many places of > ipv4 and ipv6 since commit 8d7017fd621d ("blackhole_netdev: use > blackhole_netdev to invalidate dst entries"). > > Especially after commit faab39f63c1f ("net: allow out-of-order netdev > unregistration"), it's no longer safe to use loopback_dev that may be > freed before other netdev. Maybe add it formally in Fixes: tag. > > This patch is to set dst dev to blackhole_netdev instead of loopback_dev > in ifdown. > > Signed-off-by: Xin Long <lucien.xin@gmail.com> > --- > net/xfrm/xfrm_policy.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c > index 00bd0ecff5a1..f1876ea61fdc 100644 > --- a/net/xfrm/xfrm_policy.c > +++ b/net/xfrm/xfrm_policy.c > @@ -3744,7 +3744,7 @@ static int stale_bundle(struct dst_entry *dst) > void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev) > { > while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) { > - dst->dev = dev_net(dev)->loopback_dev; > + dst->dev = blackhole_netdev; I assume the XFRM layer is ready to deal with dst->dev set to blackhole ? No initial setup needed ? Thanks > dev_hold(dst->dev); > dev_put(dev); > } > -- > 2.31.1 >
On Fri, May 13, 2022 at 12:22 PM Eric Dumazet <edumazet@google.com> wrote: > > On Fri, May 13, 2022 at 8:47 AM Xin Long <lucien.xin@gmail.com> wrote: > > > > The global blackhole_netdev has replaced pernet loopback_dev to become the > > one given to the object that holds an netdev when ifdown in many places of > > ipv4 and ipv6 since commit 8d7017fd621d ("blackhole_netdev: use > > blackhole_netdev to invalidate dst entries"). > > > > Especially after commit faab39f63c1f ("net: allow out-of-order netdev > > unregistration"), it's no longer safe to use loopback_dev that may be > > freed before other netdev. > > Maybe add it formally in Fixes: tag. > Sure. :) Fixes: faab39f63c1f ("net: allow out-of-order netdev unregistration") > > > > This patch is to set dst dev to blackhole_netdev instead of loopback_dev > > in ifdown. > > > > Signed-off-by: Xin Long <lucien.xin@gmail.com> > > --- > > net/xfrm/xfrm_policy.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c > > index 00bd0ecff5a1..f1876ea61fdc 100644 > > --- a/net/xfrm/xfrm_policy.c > > +++ b/net/xfrm/xfrm_policy.c > > @@ -3744,7 +3744,7 @@ static int stale_bundle(struct dst_entry *dst) > > void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev) > > { > > while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) { > > - dst->dev = dev_net(dev)->loopback_dev; > > + dst->dev = blackhole_netdev; > > I assume the XFRM layer is ready to deal with dst->dev set to blackhole ? > > No initial setup needed ? I don't see why it's not ready, since it's been using loopback_dev. In early time, commit 8d7017fd621d replaced loopback_dev quite straightforward for ipv4/6. BTW, there's still another one left in dn_dst_ifdown(), I will fix it in another patch. Thanks. > > Thanks > > > dev_hold(dst->dev); > > dev_put(dev); > > } > > -- > > 2.31.1 > >
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 00bd0ecff5a1..f1876ea61fdc 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -3744,7 +3744,7 @@ static int stale_bundle(struct dst_entry *dst) void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev) { while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) { - dst->dev = dev_net(dev)->loopback_dev; + dst->dev = blackhole_netdev; dev_hold(dst->dev); dev_put(dev); }
The global blackhole_netdev has replaced pernet loopback_dev to become the one given to the object that holds an netdev when ifdown in many places of ipv4 and ipv6 since commit 8d7017fd621d ("blackhole_netdev: use blackhole_netdev to invalidate dst entries"). Especially after commit faab39f63c1f ("net: allow out-of-order netdev unregistration"), it's no longer safe to use loopback_dev that may be freed before other netdev. This patch is to set dst dev to blackhole_netdev instead of loopback_dev in ifdown. Signed-off-by: Xin Long <lucien.xin@gmail.com> --- net/xfrm/xfrm_policy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)