Commit f592f804 authored Oct 24, 2018 by Taehee Yoo Committed by Daniel Borkmann Oct 26, 2018

bpf: devmap: fix wrong interface selection in notifier_call



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: 2ddf71e2 ("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>

parent 42d0f71c

kernel/bpf/devmap.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -512,8 +512,7 @@ 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)

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