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| author | Sven Eckelmann <sven@narfation.org> | 2022-02-28 00:01:24 +0100 |
|---|---|---|
| committer | Simon Wunderlich <sw@simonwunderlich.de> | 2022-03-02 09:01:25 +0100 |
| commit | 690bb6fb64f5dc7437317153902573ecad67593d (patch) | |
| tree | 5148040738379a87c3c8a713cda24da5cc7a05c3 /net/batman-adv | |
| parent | e783362eb54cd99b2cac8b3a9aeac942e6f6ac07 (diff) | |
| download | lwn-690bb6fb64f5dc7437317153902573ecad67593d.tar.gz lwn-690bb6fb64f5dc7437317153902573ecad67593d.zip | |
batman-adv: Request iflink once in batadv-on-batadv check
There is no need to call dev_get_iflink multiple times for the same
net_device in batadv_is_on_batman_iface. And since some of the
.ndo_get_iflink callbacks are dynamic (for example via RCUs like in
vxcan_get_iflink), it could easily happen that the returned values are not
stable. The pre-checks before __dev_get_by_index are then of course bogus.
Fixes: b7eddd0b3950 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'net/batman-adv')
| -rw-r--r-- | net/batman-adv/hard-interface.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index 8a2b78f9c4b2..35aa1122043b 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -149,22 +149,23 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev) struct net *net = dev_net(net_dev); struct net_device *parent_dev; struct net *parent_net; + int iflink; bool ret; /* check if this is a batman-adv mesh interface */ if (batadv_softif_is_valid(net_dev)) return true; + iflink = dev_get_iflink(net_dev); + /* no more parents..stop recursion */ - if (dev_get_iflink(net_dev) == 0 || - dev_get_iflink(net_dev) == net_dev->ifindex) + if (iflink == 0 || iflink == net_dev->ifindex) return false; parent_net = batadv_getlink_net(net_dev, net); /* recurse over the parent device */ - parent_dev = __dev_get_by_index((struct net *)parent_net, - dev_get_iflink(net_dev)); + parent_dev = __dev_get_by_index((struct net *)parent_net, iflink); /* if we got a NULL parent_dev there is something broken.. */ if (!parent_dev) { pr_err("Cannot find parent device\n"); |