Sashiko reports that it is technically possible that we got the device
reference, but by the time we're linking it to the OVS datapath, it
may be already in the process of being deleted. In this case if the
notifier wins the race for RTNL, it will see that the device is not
yet in the OVS datapath (ovs_netdev_get_vport() will fail in the
dp_device_event()) and will do nothing. Then the ovs_netdev_link()
will take the RTNL and link the unregistering device to OVS datapath.
Eventually, netdev_wait_allrefs_any() will re-broadcast the event and
the device will be properly detached, but it will take at least a
second before that happens, so it's not something we should rely on.
Let's avoid linking the non-registered device in the first place.
Note: As per documentation, RTNL doesn't protect the reg_state, but
it actually does for all the state transitions we care about here,
so it should not be necessary to use READ_ONCE or taking the instance
lock. We can still do that, but we have a few more places even in
this file where the reg_state is accessed without those while under
RTNL, and many more places like this across the kernel code, so it
might make more sense to change all of them in a more centralized
fashion in the future, if necessary.
Fixes: ccb1352e76 ("net: Add Open vSwitch kernel components.")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://patch.msgid.link/20260514184702.2461435-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
vports are used concurrently and protected by RCU, so netdev_put()
must happen after the RCU grace period. So, either in an RCU call or
after the synchronize_net(). The rtnl_delete_link() must happen under
RTNL and so can't be executed in RCU context. Calling synchronize_net()
while holding RTNL is not a good idea for performance and system
stability under load in general, so calling netdev_put() in RCU call
is the right solution here.
However,
when the device is deleted, rtnl_unlock() will call netdev_run_todo()
and block until all the references are gone. In the current code this
means that we never reach the call_rcu() and the vport is never freed
and the reference is never released, causing a self-deadlock on device
removal.
Fix that by moving the rcu_call() before the rtnl_unlock(), so the
scheduled RCU callback will be executed when synchronize_net() is
called from the rtnl_unlock()->netdev_run_todo() while the RTNL itself
is already released.
Fixes: 6931d21f87 ("openvswitch: defer tunnel netdev_put to RCU release")
Cc: stable@vger.kernel.org
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20260430233848.440994-2-i.maximets@ovn.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When a tunnel vport is created it first creates the tunnel device, e.g.,
with geneve_dev_create_fb(), then it calls ovs_netdev_link() to take a
reference and link it to the device that represents openvswitch datapath.
The creation of the device is happening under RTNL, but then RTNL is
released and re-acquired to find the device by name. It is technically
possible for the tunnel device to be re-named or deleted within that
window while RTNL is not held, and some other device created in its
place. This will cause a non-tunnel device to be referenced in the
vport and tunnel-specific functions used on it, e.g. vxlan_get_options()
that directly casts the private netdev data into a struct vxlan_dev
causing an invalid memory access:
BUG: KASAN: slab-use-after-free in vxlan_get_options+0x323/0x3a0
vxlan_get_options+0x323/0x3a0
ovs_vport_cmd_new+0x6e3/0xd30
Fix that by taking a reference to the just created device before
releasing RTNL. This ensures that the device in the vport is always
the one that was just created. The search by name is only needed
for a standard vport-netdev that links pre-existing devices, so that
functionality and device type checks are moved to netdev_create().
It is also awkward that ovs_netdev_link() takes ownership of the vport
and destroys it on failure. It doesn't know the type of the port it is
dealing with, so we need to pass down the indicator that it's a tunnel,
so the link can be properly deleted on failure.
It's possible to refactor the logic to make the ovs_netdev_link() do
only the linking part and let the callers perform a proper destruction,
but it will be much more code for each legacy tunnel port type, so it
is not worth it for the bug fix.
Fixes: 614732eaa1 ("openvswitch: Use regular VXLAN net_device device")
Reported-by: Yuan Tan <tanyuan98@outlook.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Reported-by: Yang Yang <n05ec@lzu.edu.cn>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://patch.msgid.link/20260430213349.407991-1-i.maximets@ovn.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
ovs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already
detached the device. Dropping the netdev reference in destroy can race
with concurrent readers that still observe vport->dev.
Do not release vport->dev in ovs_netdev_tunnel_destroy(). Instead, let
vport_netdev_free() drop the reference from the RCU callback, matching
the non-tunnel destroy path and avoiding additional synchronization
under RTNL.
Fixes: a9020fde67 ("openvswitch: Move tunnel destroy function to oppenvswitch module.")
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Tested-by: Ao Zhou <n05ec@lzu.edu.cn>
Co-developed-by: Yuan Tan <tanyuan98@outlook.com>
Signed-off-by: Yuan Tan <tanyuan98@outlook.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Yang Yang <n05ec@lzu.edu.cn>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Link: https://patch.msgid.link/20260319074241.3405262-1-n05ec@lzu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The openvswitch teardown code will immediately call
ovs_netdev_detach_dev() in response to a NETDEV_UNREGISTER notification.
It will then start the dp_notify_work workqueue, which will later end up
calling the vport destroy() callback. This callback takes the RTNL to do
another ovs_netdev_detach_port(), which in this case is unnecessary.
This causes extra pressure on the RTNL, in some cases leading to
"unregister_netdevice: waiting for XX to become free" warnings on
teardown.
We can straight-forwardly avoid the extra RTNL lock acquisition by
checking the device flags before taking the lock, and skip the locking
altogether if the IFF_OVS_DATAPATH flag has already been unset.
Fixes: b07c26511e ("openvswitch: fix vport-netdev unregister")
Tested-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20251211115006.228876-1-toke@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This patch use the new helper unregister_netdevice_many_notify() for
rtnl_delete_link(), so that the kernel could reply unicast when userspace
set NLM_F_ECHO flag to request the new created interface info.
At the same time, the parameters of rtnl_delete_link() need to be updated
since we need nlmsghdr and portid info.
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.
Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()
Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The 'if (dev)' statement already move into dev_{put , hold}, so remove
redundant if statements.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
'skb_push()'/'skb_postpush_rcsum()' can be replaced by an equivalent
'skb_push_rcsum()' which is less verbose.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use netif_ovs_is_port() function instead of open code.
This patch doesn't change logic.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of version 2 of the gnu general public license as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 51 franklin street fifth floor boston ma
02110 1301 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 21 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141334.228102212@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
if local is NULL pointer, and the following access of local's
dev will trigger panic, which is same as BUG_ON
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add extack arg to netdev_upper_dev_link and netdev_master_upper_dev_link
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some symbols exported to other modules are really used only by
openvswitch.ko. Remove the exports.
Tested by loading all 4 openvswitch modules, nothing breaks.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace individual implementations with the recently introduced
skb_postpush_rcsum() helper.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Tom Herbert <tom@herbertland.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/renesas/ravb_main.c
kernel/bpf/syscall.c
net/ipv4/ipmr.c
All three conflicts were cases of overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Each openvswitch tunnel vport (vxlan,gre,geneve) holds a reference
to the underlying tunnel device, but never released it when such
device is deleted.
Deleting the underlying device via the ip tool cause the kernel to
hangup in the netdev_wait_allrefs() loop.
This commit ensure that on device unregistration dp_detach_port_notify()
is called for all vports that hold the device reference, properly
releasing it.
Fixes: 614732eaa1 ("openvswitch: Use regular VXLAN net_device device")
Fixes: b2acd1dc39 ("openvswitch: Use regular GRE net_device instead of vport")
Fixes: 6b001e682e ("openvswitch: Use Geneve device.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sometimes the drivers and other code would find it handy to know some
internal information about upper device being changed. So allow upper-code
to pass information down to notifier listeners during linking.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eliminate netdev_master_upper_dev_link_private and pass priv directly as
a parameter of netdev_master_upper_dev_link.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With use of lwtunnel, we can directly call dev_queue_xmit()
rather than calling netdev vport send operation.
Following change make tunnel vport code bit cleaner.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
