linux/net/openvswitch/vport-netdev.c

254 lines
6.1 KiB

openvswitch: vport: fix race between tunnel creation and linking 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: 614732eaa12d ("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>
2026-04-30 23:32:50 +02:00
openvswitch: vport: fix race between tunnel creation and linking 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: 614732eaa12d ("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>
2026-04-30 23:32:50 +02:00
openvswitch: vport: fix race between linking and the device notifier 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: ccb1352e76cf ("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>
2026-05-14 20:46:31 +02:00
openvswitch: vport: fix race between tunnel creation and linking 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: 614732eaa12d ("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>
2026-04-30 23:32:50 +02:00
openvswitch: vport: fix race between tunnel creation and linking 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: 614732eaa12d ("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>
2026-04-30 23:32:50 +02:00
openvswitch: vport: fix race between tunnel creation and linking 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: 614732eaa12d ("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>
2026-04-30 23:32:50 +02:00
openvswitch: vport: fix race between tunnel creation and linking 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: 614732eaa12d ("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>
2026-04-30 23:32:50 +02:00
openvswitch: vport: fix race between tunnel creation and linking 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: 614732eaa12d ("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>
2026-04-30 23:32:50 +02:00
openvswitch: fix vport-netdev unregister The combination of two commits: commit 8e4e1713e4 ("openvswitch: Simplify datapath locking.") commit 2537b4dd0a ("openvswitch:: link upper device for port devices") introduced a bug where upper_dev wasn't unlinked upon netdev_unregister notification The following steps: modprobe openvswitch ovs-dpctl add-dp test ip tuntap add dev tap1 mode tap ovs-dpctl add-if test tap1 ip tuntap del dev tap1 mode tap are causing multiple warnings: [ 62.747557] gre: GRE over IPv4 demultiplexor driver [ 62.749579] openvswitch: Open vSwitch switching datapath [ 62.755087] device test entered promiscuous mode [ 62.765911] device tap1 entered promiscuous mode [ 62.766033] IPv6: ADDRCONF(NETDEV_UP): tap1: link is not ready [ 62.769017] ------------[ cut here ]------------ [ 62.769022] WARNING: CPU: 1 PID: 3267 at net/core/dev.c:5501 rollback_registered_many+0x20f/0x240() [ 62.769023] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video [ 62.769051] CPU: 1 PID: 3267 Comm: ip Not tainted 3.12.0-rc3+ #60 [ 62.769052] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 62.769053] 0000000000000009 ffff8807f25cbd28 ffffffff8175e575 0000000000000006 [ 62.769055] 0000000000000000 ffff8807f25cbd68 ffffffff8105314c ffff8807f25cbd58 [ 62.769057] ffff8807f2634000 ffff8807f25cbdc8 ffff8807f25cbd88 ffff8807f25cbdc8 [ 62.769059] Call Trace: [ 62.769062] [<ffffffff8175e575>] dump_stack+0x55/0x76 [ 62.769065] [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0 [ 62.769067] [<ffffffff8105319a>] warn_slowpath_null+0x1a/0x20 [ 62.769069] [<ffffffff8162a04f>] rollback_registered_many+0x20f/0x240 [ 62.769071] [<ffffffff8162a101>] rollback_registered+0x31/0x40 [ 62.769073] [<ffffffff8162a488>] unregister_netdevice_queue+0x58/0x90 [ 62.769075] [<ffffffff8154f900>] __tun_detach+0x140/0x340 [ 62.769077] [<ffffffff8154fb36>] tun_chr_close+0x36/0x60 [ 62.769080] [<ffffffff811bddaf>] __fput+0xff/0x260 [ 62.769082] [<ffffffff811bdf5e>] ____fput+0xe/0x10 [ 62.769084] [<ffffffff8107b515>] task_work_run+0xb5/0xe0 [ 62.769087] [<ffffffff810029b9>] do_notify_resume+0x59/0x80 [ 62.769089] [<ffffffff813a41fe>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 62.769091] [<ffffffff81770f5a>] int_signal+0x12/0x17 [ 62.769093] ---[ end trace 838756c62e156ffb ]--- [ 62.769481] ------------[ cut here ]------------ [ 62.769485] WARNING: CPU: 1 PID: 92 at fs/sysfs/inode.c:325 sysfs_hash_and_remove+0xa9/0xb0() [ 62.769486] sysfs: can not remove 'master', no directory [ 62.769486] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video [ 62.769514] CPU: 1 PID: 92 Comm: kworker/1:2 Tainted: G W 3.12.0-rc3+ #60 [ 62.769515] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 62.769518] Workqueue: events ovs_dp_notify_wq [openvswitch] [ 62.769519] 0000000000000009 ffff880807ad3ac8 ffffffff8175e575 0000000000000006 [ 62.769521] ffff880807ad3b18 ffff880807ad3b08 ffffffff8105314c ffff880807ad3b28 [ 62.769523] 0000000000000000 ffffffff81a87a1f ffff8807f2634000 ffff880037038500 [ 62.769525] Call Trace: [ 62.769528] [<ffffffff8175e575>] dump_stack+0x55/0x76 [ 62.769529] [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0 [ 62.769531] [<ffffffff81053236>] warn_slowpath_fmt+0x46/0x50 [ 62.769533] [<ffffffff8123e7e9>] sysfs_hash_and_remove+0xa9/0xb0 [ 62.769535] [<ffffffff81240e96>] sysfs_remove_link+0x26/0x30 [ 62.769538] [<ffffffff81631ef7>] __netdev_adjacent_dev_remove+0xf7/0x150 [ 62.769540] [<ffffffff81632037>] __netdev_adjacent_dev_unlink_lists+0x27/0x50 [ 62.769542] [<ffffffff8163213a>] __netdev_adjacent_dev_unlink_neighbour+0x3a/0x50 [ 62.769544] [<ffffffff8163218d>] netdev_upper_dev_unlink+0x3d/0x140 [ 62.769548] [<ffffffffa033c2db>] netdev_destroy+0x4b/0x80 [openvswitch] [ 62.769550] [<ffffffffa033b696>] ovs_vport_del+0x46/0x60 [openvswitch] [ 62.769552] [<ffffffffa0335314>] ovs_dp_detach_port+0x44/0x60 [openvswitch] [ 62.769555] [<ffffffffa0336574>] ovs_dp_notify_wq+0xb4/0x150 [openvswitch] [ 62.769557] [<ffffffff81075c28>] process_one_work+0x1d8/0x6a0 [ 62.769559] [<ffffffff81075bc8>] ? process_one_work+0x178/0x6a0 [ 62.769562] [<ffffffff8107659b>] worker_thread+0x11b/0x370 [ 62.769564] [<ffffffff81076480>] ? rescuer_thread+0x350/0x350 [ 62.769566] [<ffffffff8107f44a>] kthread+0xea/0xf0 [ 62.769568] [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150 [ 62.769570] [<ffffffff81770bac>] ret_from_fork+0x7c/0xb0 [ 62.769572] [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150 [ 62.769573] ---[ end trace 838756c62e156ffc ]--- [ 62.769574] ------------[ cut here ]------------ [ 62.769576] WARNING: CPU: 1 PID: 92 at fs/sysfs/inode.c:325 sysfs_hash_and_remove+0xa9/0xb0() [ 62.769577] sysfs: can not remove 'upper_test', no directory [ 62.769577] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video [ 62.769603] CPU: 1 PID: 92 Comm: kworker/1:2 Tainted: G W 3.12.0-rc3+ #60 [ 62.769604] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 62.769606] Workqueue: events ovs_dp_notify_wq [openvswitch] [ 62.769607] 0000000000000009 ffff880807ad3ac8 ffffffff8175e575 0000000000000006 [ 62.769609] ffff880807ad3b18 ffff880807ad3b08 ffffffff8105314c ffff880807ad3b58 [ 62.769611] 0000000000000000 ffff880807ad3bd9 ffff8807f2634000 ffff880037038500 [ 62.769613] Call Trace: [ 62.769615] [<ffffffff8175e575>] dump_stack+0x55/0x76 [ 62.769617] [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0 [ 62.769619] [<ffffffff81053236>] warn_slowpath_fmt+0x46/0x50 [ 62.769621] [<ffffffff8123e7e9>] sysfs_hash_and_remove+0xa9/0xb0 [ 62.769622] [<ffffffff81240e96>] sysfs_remove_link+0x26/0x30 [ 62.769624] [<ffffffff81631f22>] __netdev_adjacent_dev_remove+0x122/0x150 [ 62.769627] [<ffffffff81632037>] __netdev_adjacent_dev_unlink_lists+0x27/0x50 [ 62.769629] [<ffffffff8163213a>] __netdev_adjacent_dev_unlink_neighbour+0x3a/0x50 [ 62.769631] [<ffffffff8163218d>] netdev_upper_dev_unlink+0x3d/0x140 [ 62.769633] [<ffffffffa033c2db>] netdev_destroy+0x4b/0x80 [openvswitch] [ 62.769636] [<ffffffffa033b696>] ovs_vport_del+0x46/0x60 [openvswitch] [ 62.769638] [<ffffffffa0335314>] ovs_dp_detach_port+0x44/0x60 [openvswitch] [ 62.769640] [<ffffffffa0336574>] ovs_dp_notify_wq+0xb4/0x150 [openvswitch] [ 62.769642] [<ffffffff81075c28>] process_one_work+0x1d8/0x6a0 [ 62.769644] [<ffffffff81075bc8>] ? process_one_work+0x178/0x6a0 [ 62.769646] [<ffffffff8107659b>] worker_thread+0x11b/0x370 [ 62.769648] [<ffffffff81076480>] ? rescuer_thread+0x350/0x350 [ 62.769650] [<ffffffff8107f44a>] kthread+0xea/0xf0 [ 62.769652] [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150 [ 62.769654] [<ffffffff81770bac>] ret_from_fork+0x7c/0xb0 [ 62.769656] [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150 [ 62.769657] ---[ end trace 838756c62e156ffd ]--- [ 62.769724] device tap1 left promiscuous mode This patch also affects moving devices between net namespaces. OVS used to ignore netns move notifications which caused problems. Like: ovs-dpctl add-if test tap1 ip link set tap1 netns 3512 and then removing tap1 inside the namespace will cause hang on missing dev_put. With this patch OVS will detach dev upon receiving netns move event. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: Jesse Gross <jesse@nicira.com>
2013-10-15 14:54:11 -07:00
net: openvswitch: Avoid releasing netdev before teardown completes The patch cited in the Fixes tag below changed the teardown code for OVS ports to no longer unconditionally take the RTNL. After this change, the netdev_destroy() callback can proceed immediately to the call_rcu() invocation if the IFF_OVS_DATAPATH flag is already cleared on the netdev. The ovs_netdev_detach_dev() function clears the flag before completing the unregistration, and if it gets preempted after clearing the flag (as can happen on an -rt kernel), netdev_destroy() can complete and the device can be freed before the unregistration completes. This leads to a splat like: [ 998.393867] Oops: general protection fault, probably for non-canonical address 0xff00000001000239: 0000 [#1] SMP PTI [ 998.393877] CPU: 42 UID: 0 PID: 55177 Comm: ip Kdump: loaded Not tainted 6.12.0-211.1.1.el10_2.x86_64+rt #1 PREEMPT_RT [ 998.393886] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.24.0 03/27/2025 [ 998.393889] RIP: 0010:dev_set_promiscuity+0x8d/0xa0 [ 998.393901] Code: 00 00 75 d8 48 8b 53 08 48 83 ba b0 02 00 00 00 75 ca 48 83 c4 08 5b c3 cc cc cc cc 48 83 bf 48 09 00 00 00 75 91 48 8b 47 08 <48> 83 b8 b0 02 00 00 00 74 97 eb 81 0f 1f 80 00 00 00 00 90 90 90 [ 998.393906] RSP: 0018:ffffce5864a5f6a0 EFLAGS: 00010246 [ 998.393912] RAX: ff00000000ffff89 RBX: ffff894d0adf5a05 RCX: 0000000000000000 [ 998.393917] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff894d0adf5a05 [ 998.393921] RBP: ffff894d19252000 R08: ffff894d19252000 R09: 0000000000000000 [ 998.393924] R10: ffff894d19252000 R11: ffff894d192521b8 R12: 0000000000000006 [ 998.393927] R13: ffffce5864a5f738 R14: 00000000ffffffe2 R15: 0000000000000000 [ 998.393931] FS: 00007fad61971800(0000) GS:ffff894cc0140000(0000) knlGS:0000000000000000 [ 998.393936] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 998.393940] CR2: 000055df0a2a6e40 CR3: 000000011c7fe003 CR4: 00000000007726f0 [ 998.393944] PKRU: 55555554 [ 998.393946] Call Trace: [ 998.393949] <TASK> [ 998.393952] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393961] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393975] ? dp_device_event+0x41/0x80 [openvswitch] [ 998.394009] ? __die_body.cold+0x8/0x12 [ 998.394016] ? die_addr+0x3c/0x60 [ 998.394027] ? exc_general_protection+0x16d/0x390 [ 998.394042] ? asm_exc_general_protection+0x26/0x30 [ 998.394058] ? dev_set_promiscuity+0x8d/0xa0 [ 998.394066] ? ovs_netdev_detach_dev+0x3a/0x80 [openvswitch] [ 998.394092] dp_device_event+0x41/0x80 [openvswitch] [ 998.394102] notifier_call_chain+0x5a/0xd0 [ 998.394106] unregister_netdevice_many_notify+0x51b/0xa60 [ 998.394110] rtnl_dellink+0x169/0x3e0 [ 998.394121] ? rt_mutex_slowlock.constprop.0+0x95/0xd0 [ 998.394125] rtnetlink_rcv_msg+0x142/0x3f0 [ 998.394128] ? avc_has_perm_noaudit+0x69/0xf0 [ 998.394130] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 998.394132] netlink_rcv_skb+0x50/0x100 [ 998.394138] netlink_unicast+0x292/0x3f0 [ 998.394141] netlink_sendmsg+0x21b/0x470 [ 998.394145] ____sys_sendmsg+0x39d/0x3d0 [ 998.394149] ___sys_sendmsg+0x9a/0xe0 [ 998.394156] __sys_sendmsg+0x7a/0xd0 [ 998.394160] do_syscall_64+0x7f/0x170 [ 998.394162] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 998.394165] RIP: 0033:0x7fad61bf4724 [ 998.394188] Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d c5 e9 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 [ 998.394189] RSP: 002b:00007ffd7e2f7cb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e [ 998.394191] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fad61bf4724 [ 998.394193] RDX: 0000000000000000 RSI: 00007ffd7e2f7d20 RDI: 0000000000000003 [ 998.394194] RBP: 00007ffd7e2f7d90 R08: 0000000000000010 R09: 000000000000003f [ 998.394195] R10: 000055df11558010 R11: 0000000000000202 R12: 00007ffd7e2f8380 [ 998.394196] R13: 0000000069b233d7 R14: 000055df0a256040 R15: 0000000000000000 [ 998.394200] </TASK> To fix this, reorder the operations in ovs_netdev_detach_dev() to only clear the flag after completing the other operations, and introduce an smp_wmb() to make the ordering requirement explicit. The smp_wmb() is paired with a full smp_mb() in netdev_destroy() to make sure the call_rcu() invocation does not happen before the unregister operations are visible. Reported-by: Minxi Hou <mhou@redhat.com> Tested-by: Minxi Hou <mhou@redhat.com> Fixes: 549822767630 ("net: openvswitch: Avoid needlessly taking the RTNL on vport destroy") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20260318155554.1133405-1-toke@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-18 16:55:51 +01:00
openvswitch: fix vport-netdev unregister The combination of two commits: commit 8e4e1713e4 ("openvswitch: Simplify datapath locking.") commit 2537b4dd0a ("openvswitch:: link upper device for port devices") introduced a bug where upper_dev wasn't unlinked upon netdev_unregister notification The following steps: modprobe openvswitch ovs-dpctl add-dp test ip tuntap add dev tap1 mode tap ovs-dpctl add-if test tap1 ip tuntap del dev tap1 mode tap are causing multiple warnings: [ 62.747557] gre: GRE over IPv4 demultiplexor driver [ 62.749579] openvswitch: Open vSwitch switching datapath [ 62.755087] device test entered promiscuous mode [ 62.765911] device tap1 entered promiscuous mode [ 62.766033] IPv6: ADDRCONF(NETDEV_UP): tap1: link is not ready [ 62.769017] ------------[ cut here ]------------ [ 62.769022] WARNING: CPU: 1 PID: 3267 at net/core/dev.c:5501 rollback_registered_many+0x20f/0x240() [ 62.769023] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video [ 62.769051] CPU: 1 PID: 3267 Comm: ip Not tainted 3.12.0-rc3+ #60 [ 62.769052] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 62.769053] 0000000000000009 ffff8807f25cbd28 ffffffff8175e575 0000000000000006 [ 62.769055] 0000000000000000 ffff8807f25cbd68 ffffffff8105314c ffff8807f25cbd58 [ 62.769057] ffff8807f2634000 ffff8807f25cbdc8 ffff8807f25cbd88 ffff8807f25cbdc8 [ 62.769059] Call Trace: [ 62.769062] [<ffffffff8175e575>] dump_stack+0x55/0x76 [ 62.769065] [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0 [ 62.769067] [<ffffffff8105319a>] warn_slowpath_null+0x1a/0x20 [ 62.769069] [<ffffffff8162a04f>] rollback_registered_many+0x20f/0x240 [ 62.769071] [<ffffffff8162a101>] rollback_registered+0x31/0x40 [ 62.769073] [<ffffffff8162a488>] unregister_netdevice_queue+0x58/0x90 [ 62.769075] [<ffffffff8154f900>] __tun_detach+0x140/0x340 [ 62.769077] [<ffffffff8154fb36>] tun_chr_close+0x36/0x60 [ 62.769080] [<ffffffff811bddaf>] __fput+0xff/0x260 [ 62.769082] [<ffffffff811bdf5e>] ____fput+0xe/0x10 [ 62.769084] [<ffffffff8107b515>] task_work_run+0xb5/0xe0 [ 62.769087] [<ffffffff810029b9>] do_notify_resume+0x59/0x80 [ 62.769089] [<ffffffff813a41fe>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 62.769091] [<ffffffff81770f5a>] int_signal+0x12/0x17 [ 62.769093] ---[ end trace 838756c62e156ffb ]--- [ 62.769481] ------------[ cut here ]------------ [ 62.769485] WARNING: CPU: 1 PID: 92 at fs/sysfs/inode.c:325 sysfs_hash_and_remove+0xa9/0xb0() [ 62.769486] sysfs: can not remove 'master', no directory [ 62.769486] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video [ 62.769514] CPU: 1 PID: 92 Comm: kworker/1:2 Tainted: G W 3.12.0-rc3+ #60 [ 62.769515] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 62.769518] Workqueue: events ovs_dp_notify_wq [openvswitch] [ 62.769519] 0000000000000009 ffff880807ad3ac8 ffffffff8175e575 0000000000000006 [ 62.769521] ffff880807ad3b18 ffff880807ad3b08 ffffffff8105314c ffff880807ad3b28 [ 62.769523] 0000000000000000 ffffffff81a87a1f ffff8807f2634000 ffff880037038500 [ 62.769525] Call Trace: [ 62.769528] [<ffffffff8175e575>] dump_stack+0x55/0x76 [ 62.769529] [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0 [ 62.769531] [<ffffffff81053236>] warn_slowpath_fmt+0x46/0x50 [ 62.769533] [<ffffffff8123e7e9>] sysfs_hash_and_remove+0xa9/0xb0 [ 62.769535] [<ffffffff81240e96>] sysfs_remove_link+0x26/0x30 [ 62.769538] [<ffffffff81631ef7>] __netdev_adjacent_dev_remove+0xf7/0x150 [ 62.769540] [<ffffffff81632037>] __netdev_adjacent_dev_unlink_lists+0x27/0x50 [ 62.769542] [<ffffffff8163213a>] __netdev_adjacent_dev_unlink_neighbour+0x3a/0x50 [ 62.769544] [<ffffffff8163218d>] netdev_upper_dev_unlink+0x3d/0x140 [ 62.769548] [<ffffffffa033c2db>] netdev_destroy+0x4b/0x80 [openvswitch] [ 62.769550] [<ffffffffa033b696>] ovs_vport_del+0x46/0x60 [openvswitch] [ 62.769552] [<ffffffffa0335314>] ovs_dp_detach_port+0x44/0x60 [openvswitch] [ 62.769555] [<ffffffffa0336574>] ovs_dp_notify_wq+0xb4/0x150 [openvswitch] [ 62.769557] [<ffffffff81075c28>] process_one_work+0x1d8/0x6a0 [ 62.769559] [<ffffffff81075bc8>] ? process_one_work+0x178/0x6a0 [ 62.769562] [<ffffffff8107659b>] worker_thread+0x11b/0x370 [ 62.769564] [<ffffffff81076480>] ? rescuer_thread+0x350/0x350 [ 62.769566] [<ffffffff8107f44a>] kthread+0xea/0xf0 [ 62.769568] [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150 [ 62.769570] [<ffffffff81770bac>] ret_from_fork+0x7c/0xb0 [ 62.769572] [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150 [ 62.769573] ---[ end trace 838756c62e156ffc ]--- [ 62.769574] ------------[ cut here ]------------ [ 62.769576] WARNING: CPU: 1 PID: 92 at fs/sysfs/inode.c:325 sysfs_hash_and_remove+0xa9/0xb0() [ 62.769577] sysfs: can not remove 'upper_test', no directory [ 62.769577] Modules linked in: openvswitch gre vxlan ip_tunnel libcrc32c ip6table_filter ip6_tables ebtable_nat ebtables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack xt_CHECKSUM iptable_mangle ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc vhost_net macvtap macvlan vhost kvm_intel kvm dm_crypt iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi hid_generic mxm_wmi eeepc_wmi asus_wmi sparse_keymap dm_multipath psmouse serio_raw usbhid hid parport_pc ppdev firewire_ohci lpc_ich firewire_core e1000e crc_itu_t binfmt_misc igb dca ptp pps_core mac_hid wmi lp parport i2o_config i2o_block video [ 62.769603] CPU: 1 PID: 92 Comm: kworker/1:2 Tainted: G W 3.12.0-rc3+ #60 [ 62.769604] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 62.769606] Workqueue: events ovs_dp_notify_wq [openvswitch] [ 62.769607] 0000000000000009 ffff880807ad3ac8 ffffffff8175e575 0000000000000006 [ 62.769609] ffff880807ad3b18 ffff880807ad3b08 ffffffff8105314c ffff880807ad3b58 [ 62.769611] 0000000000000000 ffff880807ad3bd9 ffff8807f2634000 ffff880037038500 [ 62.769613] Call Trace: [ 62.769615] [<ffffffff8175e575>] dump_stack+0x55/0x76 [ 62.769617] [<ffffffff8105314c>] warn_slowpath_common+0x8c/0xc0 [ 62.769619] [<ffffffff81053236>] warn_slowpath_fmt+0x46/0x50 [ 62.769621] [<ffffffff8123e7e9>] sysfs_hash_and_remove+0xa9/0xb0 [ 62.769622] [<ffffffff81240e96>] sysfs_remove_link+0x26/0x30 [ 62.769624] [<ffffffff81631f22>] __netdev_adjacent_dev_remove+0x122/0x150 [ 62.769627] [<ffffffff81632037>] __netdev_adjacent_dev_unlink_lists+0x27/0x50 [ 62.769629] [<ffffffff8163213a>] __netdev_adjacent_dev_unlink_neighbour+0x3a/0x50 [ 62.769631] [<ffffffff8163218d>] netdev_upper_dev_unlink+0x3d/0x140 [ 62.769633] [<ffffffffa033c2db>] netdev_destroy+0x4b/0x80 [openvswitch] [ 62.769636] [<ffffffffa033b696>] ovs_vport_del+0x46/0x60 [openvswitch] [ 62.769638] [<ffffffffa0335314>] ovs_dp_detach_port+0x44/0x60 [openvswitch] [ 62.769640] [<ffffffffa0336574>] ovs_dp_notify_wq+0xb4/0x150 [openvswitch] [ 62.769642] [<ffffffff81075c28>] process_one_work+0x1d8/0x6a0 [ 62.769644] [<ffffffff81075bc8>] ? process_one_work+0x178/0x6a0 [ 62.769646] [<ffffffff8107659b>] worker_thread+0x11b/0x370 [ 62.769648] [<ffffffff81076480>] ? rescuer_thread+0x350/0x350 [ 62.769650] [<ffffffff8107f44a>] kthread+0xea/0xf0 [ 62.769652] [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150 [ 62.769654] [<ffffffff81770bac>] ret_from_fork+0x7c/0xb0 [ 62.769656] [<ffffffff8107f360>] ? flush_kthread_worker+0x150/0x150 [ 62.769657] ---[ end trace 838756c62e156ffd ]--- [ 62.769724] device tap1 left promiscuous mode This patch also affects moving devices between net namespaces. OVS used to ignore netns move notifications which caused problems. Like: ovs-dpctl add-if test tap1 ip link set tap1 netns 3512 and then removing tap1 inside the namespace will cause hang on missing dev_put. With this patch OVS will detach dev upon receiving netns move event. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: Jesse Gross <jesse@nicira.com>
2013-10-15 14:54:11 -07:00
net: openvswitch: Avoid releasing netdev before teardown completes The patch cited in the Fixes tag below changed the teardown code for OVS ports to no longer unconditionally take the RTNL. After this change, the netdev_destroy() callback can proceed immediately to the call_rcu() invocation if the IFF_OVS_DATAPATH flag is already cleared on the netdev. The ovs_netdev_detach_dev() function clears the flag before completing the unregistration, and if it gets preempted after clearing the flag (as can happen on an -rt kernel), netdev_destroy() can complete and the device can be freed before the unregistration completes. This leads to a splat like: [ 998.393867] Oops: general protection fault, probably for non-canonical address 0xff00000001000239: 0000 [#1] SMP PTI [ 998.393877] CPU: 42 UID: 0 PID: 55177 Comm: ip Kdump: loaded Not tainted 6.12.0-211.1.1.el10_2.x86_64+rt #1 PREEMPT_RT [ 998.393886] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.24.0 03/27/2025 [ 998.393889] RIP: 0010:dev_set_promiscuity+0x8d/0xa0 [ 998.393901] Code: 00 00 75 d8 48 8b 53 08 48 83 ba b0 02 00 00 00 75 ca 48 83 c4 08 5b c3 cc cc cc cc 48 83 bf 48 09 00 00 00 75 91 48 8b 47 08 <48> 83 b8 b0 02 00 00 00 74 97 eb 81 0f 1f 80 00 00 00 00 90 90 90 [ 998.393906] RSP: 0018:ffffce5864a5f6a0 EFLAGS: 00010246 [ 998.393912] RAX: ff00000000ffff89 RBX: ffff894d0adf5a05 RCX: 0000000000000000 [ 998.393917] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff894d0adf5a05 [ 998.393921] RBP: ffff894d19252000 R08: ffff894d19252000 R09: 0000000000000000 [ 998.393924] R10: ffff894d19252000 R11: ffff894d192521b8 R12: 0000000000000006 [ 998.393927] R13: ffffce5864a5f738 R14: 00000000ffffffe2 R15: 0000000000000000 [ 998.393931] FS: 00007fad61971800(0000) GS:ffff894cc0140000(0000) knlGS:0000000000000000 [ 998.393936] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 998.393940] CR2: 000055df0a2a6e40 CR3: 000000011c7fe003 CR4: 00000000007726f0 [ 998.393944] PKRU: 55555554 [ 998.393946] Call Trace: [ 998.393949] <TASK> [ 998.393952] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393961] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393975] ? dp_device_event+0x41/0x80 [openvswitch] [ 998.394009] ? __die_body.cold+0x8/0x12 [ 998.394016] ? die_addr+0x3c/0x60 [ 998.394027] ? exc_general_protection+0x16d/0x390 [ 998.394042] ? asm_exc_general_protection+0x26/0x30 [ 998.394058] ? dev_set_promiscuity+0x8d/0xa0 [ 998.394066] ? ovs_netdev_detach_dev+0x3a/0x80 [openvswitch] [ 998.394092] dp_device_event+0x41/0x80 [openvswitch] [ 998.394102] notifier_call_chain+0x5a/0xd0 [ 998.394106] unregister_netdevice_many_notify+0x51b/0xa60 [ 998.394110] rtnl_dellink+0x169/0x3e0 [ 998.394121] ? rt_mutex_slowlock.constprop.0+0x95/0xd0 [ 998.394125] rtnetlink_rcv_msg+0x142/0x3f0 [ 998.394128] ? avc_has_perm_noaudit+0x69/0xf0 [ 998.394130] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 998.394132] netlink_rcv_skb+0x50/0x100 [ 998.394138] netlink_unicast+0x292/0x3f0 [ 998.394141] netlink_sendmsg+0x21b/0x470 [ 998.394145] ____sys_sendmsg+0x39d/0x3d0 [ 998.394149] ___sys_sendmsg+0x9a/0xe0 [ 998.394156] __sys_sendmsg+0x7a/0xd0 [ 998.394160] do_syscall_64+0x7f/0x170 [ 998.394162] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 998.394165] RIP: 0033:0x7fad61bf4724 [ 998.394188] Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d c5 e9 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 [ 998.394189] RSP: 002b:00007ffd7e2f7cb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e [ 998.394191] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fad61bf4724 [ 998.394193] RDX: 0000000000000000 RSI: 00007ffd7e2f7d20 RDI: 0000000000000003 [ 998.394194] RBP: 00007ffd7e2f7d90 R08: 0000000000000010 R09: 000000000000003f [ 998.394195] R10: 000055df11558010 R11: 0000000000000202 R12: 00007ffd7e2f8380 [ 998.394196] R13: 0000000069b233d7 R14: 000055df0a256040 R15: 0000000000000000 [ 998.394200] </TASK> To fix this, reorder the operations in ovs_netdev_detach_dev() to only clear the flag after completing the other operations, and introduce an smp_wmb() to make the ordering requirement explicit. The smp_wmb() is paired with a full smp_mb() in netdev_destroy() to make sure the call_rcu() invocation does not happen before the unregister operations are visible. Reported-by: Minxi Hou <mhou@redhat.com> Tested-by: Minxi Hou <mhou@redhat.com> Fixes: 549822767630 ("net: openvswitch: Avoid needlessly taking the RTNL on vport destroy") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20260318155554.1133405-1-toke@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-18 16:55:51 +01:00