[PATCH AUTOSEL 4.19 124/237] bpf: devmap: fix wrong interface selection in notifier_call
From: Sasha Levin <sashal@kernel.org>
Date: 2019-11-16 15:44:03
Also in:
bpf, lkml, stable
Subsystem:
bpf [general] (safe dynamic programs and tools), the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend
From: Taehee Yoo <ap420073@gmail.com>
[ 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: 2ddf71e23cc2 ("net: add notifier hooks for devmap bpf map")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Song Liu <redacted>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/bpf/devmap.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index fc500ca464d00..1defea4b27553 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c@@ -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)
--
2.20.1