diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-04-02 10:35:19 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-04-03 14:40:36 -0700 |
| commit | b120e4432f9f56c7103133d6a11245e617695adb (patch) | |
| tree | 7c98af2e4ccd98f7c2f47ef255450fa2858f1afd | |
| parent | e16a0d36777b572196de4944aaa196adf828eb8e (diff) | |
net: lapbether: handle NETDEV_PRE_TYPE_CHANGE
lapbeth_data_transmit() expects the underlying device type
to be ARPHRD_ETHER.
Returning NOTIFY_BAD from lapbeth_device_event() makes sure
bonding driver can not break this expectation.
Fixes: 872254dd6b1f ("net/bonding: Enable bonding to enslave non ARPHRD_ETHER")
Reported-by: syzbot+d8c285748fa7292580a9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/69cd22a1.050a0220.70c3a.0002.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin Schiller <ms@dev.tdt.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260402103519.1201565-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/wan/lapbether.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c index f357a7ac70ac..9861c99ea56c 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -446,33 +446,36 @@ static void lapbeth_free_device(struct lapbethdev *lapbeth) static int lapbeth_device_event(struct notifier_block *this, unsigned long event, void *ptr) { - struct lapbethdev *lapbeth; struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct lapbethdev *lapbeth; if (dev_net(dev) != &init_net) return NOTIFY_DONE; - if (!dev_is_ethdev(dev) && !lapbeth_get_x25_dev(dev)) + lapbeth = lapbeth_get_x25_dev(dev); + if (!dev_is_ethdev(dev) && !lapbeth) return NOTIFY_DONE; switch (event) { case NETDEV_UP: /* New ethernet device -> new LAPB interface */ - if (!lapbeth_get_x25_dev(dev)) + if (!lapbeth) lapbeth_new_device(dev); break; case NETDEV_GOING_DOWN: /* ethernet device closes -> close LAPB interface */ - lapbeth = lapbeth_get_x25_dev(dev); if (lapbeth) dev_close(lapbeth->axdev); break; case NETDEV_UNREGISTER: /* ethernet device disappears -> remove LAPB interface */ - lapbeth = lapbeth_get_x25_dev(dev); if (lapbeth) lapbeth_free_device(lapbeth); break; + case NETDEV_PRE_TYPE_CHANGE: + /* Our underlying device type must not change. */ + if (lapbeth) + return NOTIFY_BAD; } return NOTIFY_DONE; |