From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarod Wilson Subject: [PATCH v2 net-next] net/core: ensure features get disabled on new lower devs Date: Tue, 3 Nov 2015 23:09:32 -0500 Message-ID: <1446610172-21420-1-git-send-email-jarod@redhat.com> References: <1446583017-19021-1-git-send-email-jarod@redhat.com> Cc: Jarod Wilson , "David S. Miller" , Eric Dumazet , Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , Jiri Pirko , Nikolay Aleksandrov , Michal Kubecek , Alexander Duyck , netdev@vger.kernel.org To: linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1446583017-19021-1-git-send-email-jarod@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org With moving netdev_sync_lower_features() after the .ndo_set_features calls, I neglected to verify that devices added *after* a flag had been disabled on an upper device were properly added with that flag disabled as well. This currently happens, because we exit __netdev_update_features() when we see dev->features == features for the upper dev. We can retain the optimization of leaving without calling .ndo_set_features with a bit of tweaking and a goto here. Fixes: fd867d51f889 ("net/core: generic support for disabling netdev features down stack") CC: "David S. Miller" CC: Eric Dumazet CC: Jay Vosburgh CC: Veaceslav Falico CC: Andy Gospodarek CC: Jiri Pirko CC: Nikolay Aleksandrov CC: Michal Kubecek CC: Alexander Duyck CC: netdev@vger.kernel.org Reported-by: Nikolay Aleksandrov Signed-off-by: Jarod Wilson --- v2: Based on suggestions from Alex, and with not changing err to ret, this patch actually becomes quite minimal and doesn't ugly up the code much. net/core/dev.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 8ce3f74..ab9b8d0 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6402,7 +6402,7 @@ int __netdev_update_features(struct net_device *dev) struct net_device *upper, *lower; netdev_features_t features; struct list_head *iter; - int err = 0; + int err = -1; ASSERT_RTNL(); @@ -6419,7 +6419,7 @@ int __netdev_update_features(struct net_device *dev) features = netdev_sync_upper_features(dev, upper, features); if (dev->features == features) - return 0; + goto sync_lower; netdev_dbg(dev, "Features changed: %pNF -> %pNF\n", &dev->features, &features); @@ -6434,6 +6434,7 @@ int __netdev_update_features(struct net_device *dev) return -1; } +sync_lower: /* some features must be disabled on lower devices when disabled * on an upper device (think: bonding master or bridge) */ @@ -6443,7 +6444,7 @@ int __netdev_update_features(struct net_device *dev) if (!err) dev->features = features; - return 1; + return err < 0 ? 0 : 1; } /** -- 1.8.3.1