bpf: devmap: fix wrong interface selection in notifier_call

[ Upstream commit f592f804831f1cf9d1f9966f58c80f150e6829b5 ]

The dev_map_notification() removes interface in devmap if
unregistering interface's ifindex is same.
But only checking ifindex is not enough because other netns can have
same ifindex. so that wrong interface selection could occurred.
Hence netdev pointer comparison code is added.

v2: compare netdev pointer instead of using net_eq() (Daniel Borkmann)
v1: Initial patch

Fixes: 2ddf71e23c ("net: add notifier hooks for devmap bpf map")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Taehee Yoo 2018-10-24 20:15:17 +09:00 committed by Greg Kroah-Hartman
parent 7b557dbdc5
commit 8044e741ee

View File

@ -520,8 +520,7 @@ static int dev_map_notification(struct notifier_block *notifier,
struct bpf_dtab_netdev *dev, *odev;
dev = READ_ONCE(dtab->netdev_map[i]);
if (!dev ||
dev->dev->ifindex != netdev->ifindex)
if (!dev || netdev != dev->dev)
continue;
odev = cmpxchg(&dtab->netdev_map[i], dev, NULL);
if (dev == odev)