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author | Sven Eckelmann <sven@narfation.org> | 2022-02-28 01:23:49 +0300 |
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committer | Simon Wunderlich <sw@simonwunderlich.de> | 2022-03-02 11:24:55 +0300 |
commit | 6c1f41afc1dbe59d9d3c8bb0d80b749c119aa334 (patch) | |
tree | c61eea2166c351fa2695dcde751b94d0486b464f /virt | |
parent | 6116ba09423f7d140f0460be6a1644dceaad00da (diff) | |
download | linux-6c1f41afc1dbe59d9d3c8bb0d80b749c119aa334.tar.xz |
batman-adv: Don't expect inter-netns unique iflink indices
The ifindex doesn't have to be unique for multiple network namespaces on
the same machine.
$ ip netns add test1
$ ip -net test1 link add dummy1 type dummy
$ ip netns add test2
$ ip -net test2 link add dummy2 type dummy
$ ip -net test1 link show dev dummy1
6: dummy1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 96:81:55:1e:dd:85 brd ff:ff:ff:ff:ff:ff
$ ip -net test2 link show dev dummy2
6: dummy2: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 5a:3c:af:35:07:c3 brd ff:ff:ff:ff:ff:ff
But the batman-adv code to walk through the various layers of virtual
interfaces uses this assumption because dev_get_iflink handles it
internally and doesn't return the actual netns of the iflink. And
dev_get_iflink only documents the situation where ifindex == iflink for
physical devices.
But only checking for dev->netdev_ops->ndo_get_iflink is also not an option
because ipoib_get_iflink implements it even when it sometimes returns an
iflink != ifindex and sometimes iflink == ifindex. The caller must
therefore make sure itself to check both netns and iflink + ifindex for
equality. Only when they are equal, a "physical" interface was detected
which should stop the traversal. On the other hand, vxcan_get_iflink can
also return 0 in case there was currently no valid peer. In this case, it
is still necessary to stop.
Fixes: b7eddd0b3950 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Fixes: 5ed4a460a1d3 ("batman-adv: additional checks for virtual interfaces on top of WiFi")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions