linux.git/drivers/net/wan/lapbether.c, branch v5.10.258

net: lapbether: handle NETDEV_PRE_TYPE_CHANGE

2026-06-01T15:29:09+00:00

[ Upstream commit b120e4432f9f56c7103133d6a11245e617695adb ]

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 
Cc: Martin Schiller 
Reviewed-by: Simon Horman 
Link: https://patch.msgid.link/20260402103519.1201565-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: lapbether: replace comparison to NULL with "lapbeth_get_x25_dev"

2026-06-01T15:29:09+00:00

[ Upstream commit d49859601d72baef143703c6944a4e41921f7e6e ]

According to the chackpatch.pl, comparison to NULL could
be written "lapbeth_get_x25_dev".

Signed-off-by: Peng Li 
Signed-off-by: David S. Miller 
Stable-dep-of: b120e4432f9f ("net: lapbether: handle NETDEV_PRE_TYPE_CHANGE")
Signed-off-by: Sasha Levin

net: lapbether: remove trailing whitespaces

2026-06-01T15:29:09+00:00

[ Upstream commit 2e350780ae4f2be8a2525929b6c69c2dd9591a20 ]

This patch removes trailing whitespaces.

Signed-off-by: Peng Li 
Signed-off-by: Guangbin Huang 
Signed-off-by: David S. Miller 
Stable-dep-of: b120e4432f9f ("net: lapbether: handle NETDEV_PRE_TYPE_CHANGE")
Signed-off-by: Sasha Levin

net: lapbether: Close the LAPB device before its underlying Ethernet device closes

2026-06-01T15:29:09+00:00

[ Upstream commit 536e1004d273cf55d0e6c6ab6bfe74dc60464cd2 ]

When a virtual LAPB device's underlying Ethernet device closes, the LAPB
device is also closed.

However, currently the LAPB device is closed after the Ethernet device
closes. It would be better to close it before the Ethernet device closes.
This would allow the LAPB device to transmit a last frame to notify the
other side that it is disconnecting.

Signed-off-by: Xie He 
Signed-off-by: David S. Miller 
Stable-dep-of: b120e4432f9f ("net: lapbether: handle NETDEV_PRE_TYPE_CHANGE")
Signed-off-by: Sasha Levin

net: lapbether: only support ethernet devices

2023-06-21T13:45:40+00:00

[ Upstream commit 9eed321cde22fc1afd76eac563ce19d899e0d6b2 ]

It probbaly makes no sense to support arbitrary network devices
for lapbether.

syzbot reported:

skbuff: skb_under_panic: text:ffff80008934c100 len:44 put:40 head:ffff0000d18dd200 data:ffff0000d18dd1ea tail:0x16 end:0x140 dev:bond1
kernel BUG at net/core/skbuff.c:200 !
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 5643 Comm: dhcpcd Not tainted 6.4.0-rc5-syzkaller-g4641cff8e810 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : skb_panic net/core/skbuff.c:196 [inline]
pc : skb_under_panic+0x13c/0x140 net/core/skbuff.c:210
lr : skb_panic net/core/skbuff.c:196 [inline]
lr : skb_under_panic+0x13c/0x140 net/core/skbuff.c:210
sp : ffff8000973b7260
x29: ffff8000973b7270 x28: ffff8000973b7360 x27: dfff800000000000
x26: ffff0000d85d8150 x25: 0000000000000016 x24: ffff0000d18dd1ea
x23: ffff0000d18dd200 x22: 000000000000002c x21: 0000000000000140
x20: 0000000000000028 x19: ffff80008934c100 x18: ffff8000973b68a0
x17: 0000000000000000 x16: ffff80008a43bfbc x15: 0000000000000202
x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000001
x11: 0000000000000201 x10: 0000000000000000 x9 : f22f7eb937cced00
x8 : f22f7eb937cced00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000973b6b78 x4 : ffff80008df9ee80 x3 : ffff8000805974f4
x2 : 0000000000000001 x1 : 0000000100000201 x0 : 0000000000000086
Call trace:
skb_panic net/core/skbuff.c:196 [inline]
skb_under_panic+0x13c/0x140 net/core/skbuff.c:210
skb_push+0xf0/0x108 net/core/skbuff.c:2409
ip6gre_header+0xbc/0x738 net/ipv6/ip6_gre.c:1383
dev_hard_header include/linux/netdevice.h:3137 [inline]
lapbeth_data_transmit+0x1c4/0x298 drivers/net/wan/lapbether.c:257
lapb_data_transmit+0x8c/0xb0 net/lapb/lapb_iface.c:447
lapb_transmit_buffer+0x178/0x204 net/lapb/lapb_out.c:149
lapb_send_control+0x220/0x320 net/lapb/lapb_subr.c:251
lapb_establish_data_link+0x94/0xec
lapb_device_event+0x348/0x4e0
notifier_call_chain+0x1a4/0x510 kernel/notifier.c:93
raw_notifier_call_chain+0x3c/0x50 kernel/notifier.c:461
__dev_notify_flags+0x2bc/0x544
dev_change_flags+0xd0/0x15c net/core/dev.c:8643
devinet_ioctl+0x858/0x17e4 net/ipv4/devinet.c:1150
inet_ioctl+0x2ac/0x4d8 net/ipv4/af_inet.c:979
sock_do_ioctl+0x134/0x2dc net/socket.c:1201
sock_ioctl+0x4ec/0x858 net/socket.c:1318
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191
el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
Code: aa1803e6 aa1903e7 a90023f5 947730f5 (d4210000)

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Cc: Martin Schiller 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: lapbether: fix issue of dev reference count leakage in lapbeth_device_event()

2022-11-16T08:57:10+00:00

[ Upstream commit 531705a765493655472c993627106e19f7e5a6d2 ]

When following tests are performed, it will cause dev reference counting
leakage.
a)ip link add bond2 type bond mode balance-rr
b)ip link set bond2 up
c)ifenslave -f bond2 rose1
d)ip link del bond2

When new bond device is created, the default type of the bond device is
ether. And the bond device is up, lapbeth_device_event() receives the
message and creates a new lapbeth device. In this case, the reference
count value of dev is hold once. But after "ifenslave -f bond2 rose1"
command is executed, the type of the bond device is changed to rose. When
the bond device is unregistered, lapbeth_device_event() will not put the
dev reference count.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Zhengchao Shao 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: lapbether: Prevent racing when checking whether the netif is running

2021-05-14T07:50:29+00:00

[ Upstream commit 5acd0cfbfbb5a688da1bfb1a2152b0c855115a35 ]

There are two "netif_running" checks in this driver. One is in
"lapbeth_xmit" and the other is in "lapbeth_rcv". They serve to make
sure that the LAPB APIs called in these functions are called before
"lapb_unregister" is called by the "ndo_stop" function.

However, these "netif_running" checks are unreliable, because it's
possible that immediately after "netif_running" returns true, "ndo_stop"
is called (which causes "lapb_unregister" to be called).

This patch adds locking to make sure "lapbeth_xmit" and "lapbeth_rcv" can
reliably check and ensure the netif is running while doing their work.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xie He 
Acked-by: Martin Schiller 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: lapbether: Remove netif_start_queue / netif_stop_queue

2021-03-17T16:06:15+00:00

commit f7d9d4854519fdf4d45c70a4d953438cd88e7e58 upstream.

For the devices in this driver, the default qdisc is "noqueue",
because their "tx_queue_len" is 0.

In function "__dev_queue_xmit" in "net/core/dev.c", devices with the
"noqueue" qdisc are specially handled. Packets are transmitted without
being queued after a "dev->flags & IFF_UP" check. However, it's possible
that even if this check succeeds, "ops->ndo_stop" may still have already
been called. This is because in "__dev_close_many", "ops->ndo_stop" is
called before clearing the "IFF_UP" flag.

If we call "netif_stop_queue" in "ops->ndo_stop", then it's possible in
"__dev_queue_xmit", it sees the "IFF_UP" flag is present, and then it
checks "netif_xmit_stopped" and finds that the queue is already stopped.
In this case, it will complain that:
"Virtual device ... asks to queue packet!"

To prevent "__dev_queue_xmit" from generating this complaint, we should
not call "netif_stop_queue" in "ops->ndo_stop".

We also don't need to call "netif_start_queue" in "ops->ndo_open",
because after a netdev is allocated and registered, the
"__QUEUE_STATE_DRV_XOFF" flag is initially not set, so there is no need
to call "netif_start_queue" to clear it.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xie He 
Acked-by: Martin Schiller 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

drivers/net/wan/lapbether: Make skb->protocol consistent with the header

2020-09-17T23:38:03+00:00

This driver is a virtual driver stacked on top of Ethernet interfaces.

When this driver transmits data on the Ethernet device, the skb->protocol
setting is inconsistent with the Ethernet header prepended to the skb.

This causes a user listening on the Ethernet interface with an AF_PACKET
socket, to see different sll_protocol values for incoming and outgoing
frames, because incoming frames would have this value set by parsing the
Ethernet header.

This patch changes the skb->protocol value for outgoing Ethernet frames,
making it consistent with the Ethernet header prepended. This makes a
user listening on the Ethernet device with an AF_PACKET socket, to see
the same sll_protocol value for incoming and outgoing frames.

Cc: Martin Schiller 
Signed-off-by: Xie He 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-09-04T01:50:48+00:00

Pull networking fixes from David Miller:

 1) Use netif_rx_ni() when necessary in batman-adv stack, from Jussi
    Kivilinna.

 2) Fix loss of RTT samples in rxrpc, from David Howells.

 3) Memory leak in hns_nic_dev_probe(), from Dignhao Liu.

 4) ravb module cannot be unloaded, fix from Yuusuke Ashizuka.

 5) We disable BH for too lokng in sctp_get_port_local(), add a
    cond_resched() here as well, from Xin Long.

 6) Fix memory leak in st95hf_in_send_cmd, from Dinghao Liu.

 7) Out of bound access in bpf_raw_tp_link_fill_link_info(), from
    Yonghong Song.

 8) Missing of_node_put() in mt7530 DSA driver, from Sumera
    Priyadarsini.

 9) Fix crash in bnxt_fw_reset_task(), from Michael Chan.

10) Fix geneve tunnel checksumming bug in hns3, from Yi Li.

11) Memory leak in rxkad_verify_response, from Dinghao Liu.

12) In tipc, don't use smp_processor_id() in preemptible context. From
    Tuong Lien.

13) Fix signedness issue in mlx4 memory allocation, from Shung-Hsi Yu.

14) Missing clk_disable_prepare() in gemini driver, from Dan Carpenter.

15) Fix ABI mismatch between driver and firmware in nfp, from Louis
    Peens.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (110 commits)
  net/smc: fix sock refcounting in case of termination
  net/smc: reset sndbuf_desc if freed
  net/smc: set rx_off for SMCR explicitly
  net/smc: fix toleration of fake add_link messages
  tg3: Fix soft lockup when tg3_reset_task() fails.
  doc: net: dsa: Fix typo in config code sample
  net: dp83867: Fix WoL SecureOn password
  nfp: flower: fix ABI mismatch between driver and firmware
  tipc: fix shutdown() of connectionless socket
  ipv6: Fix sysctl max for fib_multipath_hash_policy
  drivers/net/wan/hdlc: Change the default of hard_header_len to 0
  net: gemini: Fix another missing clk_disable_unprepare() in probe
  net: bcmgenet: fix mask check in bcmgenet_validate_flow()
  amd-xgbe: Add support for new port mode
  net: usb: dm9601: Add USB ID of Keenetic Plus DSL
  vhost: fix typo in error message
  net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init()
  pktgen: fix error message with wrong function name
  net: ethernet: ti: am65-cpsw: fix rmii 100Mbit link mode
  cxgb4: fix thermal zone device registration
  ...