diff options
| author | Taehee Yoo <ap420073@gmail.com> | 2023-05-17 17:30:10 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-05-20 08:46:37 +0300 |
| commit | ae9b15fbe63447bc1d3bba3769f409d17ca6fdf6 (patch) | |
| tree | 136d8a80feea616fd12bdc396ba5a17c85ca1277 /drivers/net/team/team.c | |
| parent | 9025944fddfed5966c8f102f1fe921ab3aee2c12 (diff) | |
| download | linux-ae9b15fbe63447bc1d3bba3769f409d17ca6fdf6.tar.xz | |
net: fix stack overflow when LRO is disabled for virtual interfaces
When the virtual interface's feature is updated, it synchronizes the
updated feature for its own lower interface.
This propagation logic should be worked as the iteration, not recursively.
But it works recursively due to the netdev notification unexpectedly.
This problem occurs when it disables LRO only for the team and bonding
interface type.
team0
|
+------+------+-----+-----+
| | | | |
team1 team2 team3 ... team200
If team0's LRO feature is updated, it generates the NETDEV_FEAT_CHANGE
event to its own lower interfaces(team1 ~ team200).
It is worked by netdev_sync_lower_features().
So, the NETDEV_FEAT_CHANGE notification logic of each lower interface
work iteratively.
But generated NETDEV_FEAT_CHANGE event is also sent to the upper
interface too.
upper interface(team0) generates the NETDEV_FEAT_CHANGE event for its own
lower interfaces again.
lower and upper interfaces receive this event and generate this
event again and again.
So, the stack overflow occurs.
But it is not the infinite loop issue.
Because the netdev_sync_lower_features() updates features before
generating the NETDEV_FEAT_CHANGE event.
Already synchronized lower interfaces skip notification logic.
So, it is just the problem that iteration logic is changed to the
recursive unexpectedly due to the notification mechanism.
Reproducer:
ip link add team0 type team
ethtool -K team0 lro on
for i in {1..200}
do
ip link add team$i master team0 type team
ethtool -K team$i lro on
done
ethtool -K team0 lro off
In order to fix it, the notifier_ctx member of bonding/team is introduced.
Reported-by: syzbot+60748c96cf5c6df8e581@syzkaller.appspotmail.com
Fixes: fd867d51f889 ("net/core: generic support for disabling netdev features down stack")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20230517143010.3596250-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/team/team.c')
| -rw-r--r-- | drivers/net/team/team.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index d10606f257c4..555b0b1e9a78 100644 --- a/drivers/net/team/team.c +++ b/drivers/net/team/team.c @@ -1629,6 +1629,7 @@ static int team_init(struct net_device *dev) team->dev = dev; team_set_no_mode(team); + team->notifier_ctx = false; team->pcpu_stats = netdev_alloc_pcpu_stats(struct team_pcpu_stats); if (!team->pcpu_stats) @@ -3022,7 +3023,11 @@ static int team_device_event(struct notifier_block *unused, team_del_slave(port->team->dev, dev); break; case NETDEV_FEAT_CHANGE: - team_compute_features(port->team); + if (!port->team->notifier_ctx) { + port->team->notifier_ctx = true; + team_compute_features(port->team); + port->team->notifier_ctx = false; + } break; case NETDEV_PRECHANGEMTU: /* Forbid to change mtu of underlaying device */ |