diff options
| author | Stanislav Fomichev <sdf@fomichev.me> | 2025-08-06 14:37:25 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 18:40:51 +0200 |
| commit | 628e233c1fefcc227fae9bdcff6be8ac92e1b4d2 (patch) | |
| tree | 24af051c2af881e6115f9c8ed2104630aeede61e | |
| parent | 1bd5214ea681584c5886fea3ba03e49f93a43c0e (diff) | |
net: lapbether: ignore ops-locked netdevs
[ Upstream commit 53898ebabe843bfa7baea9dae152797d5d0563c9 ]
Syzkaller managed to trigger lock dependency in xsk_notify via
register_netdevice. As discussed in [0], using register_netdevice
in the notifiers is problematic so skip adding lapbeth for ops-locked
devices.
xsk_notifier+0xa4/0x280 net/xdp/xsk.c:1645
notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
call_netdevice_notifiers net/core/dev.c:2282 [inline]
unregister_netdevice_many_notify+0xf9d/0x2700 net/core/dev.c:12077
unregister_netdevice_many net/core/dev.c:12140 [inline]
unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11984
register_netdevice+0x18f1/0x2270 net/core/dev.c:11149
lapbeth_new_device drivers/net/wan/lapbether.c:420 [inline]
lapbeth_device_event+0x5b1/0xbe0 drivers/net/wan/lapbether.c:462
notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
call_netdevice_notifiers net/core/dev.c:2282 [inline]
__dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9497
netif_change_flags+0x108/0x160 net/core/dev.c:9526
dev_change_flags+0xba/0x250 net/core/dev_api.c:68
devinet_ioctl+0x11d5/0x1f50 net/ipv4/devinet.c:1200
inet_ioctl+0x3a7/0x3f0 net/ipv4/af_inet.c:1001
0: https://lore.kernel.org/netdev/20250625140357.6203d0af@kernel.org/
Fixes: 4c975fd70002 ("net: hold instance lock during NETDEV_REGISTER/UP")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: syzbot+e67ea9c235b13b4f0020@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e67ea9c235b13b4f0020
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250806213726.1383379-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/net/wan/lapbether.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c index 995a7207bdf8..f357a7ac70ac 100644 --- a/drivers/net/wan/lapbether.c +++ b/drivers/net/wan/lapbether.c @@ -81,7 +81,7 @@ static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev) static __inline__ int dev_is_ethdev(struct net_device *dev) { - return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5); + return dev->type == ARPHRD_ETHER && !netdev_need_ops_lock(dev); } /* ------------------------------------------------------------------------ */ |