linux/net/core/dev.c, branch v6.3

rtnetlink: Restore RTM_NEW/DELLINK notification behavior

2023-04-13T03:47:58Z

The commits referenced below allows userspace to use the NLM_F_ECHO flag for RTM_NEW/DELLINK operations to receive unicast notifications for the affected link. Prior to these changes, applications may have relied on multicast notifications to learn the same information without specifying the NLM_F_ECHO flag. For such applications, the mentioned commits changed the behavior for requests not using NLM_F_ECHO. Multicast notifications are still received, but now use the portid of the requester and the sequence number of the request instead of zero values used previously. For the application, this message may be unexpected and likely handled as a response to the NLM_F_ACKed request, especially if it uses the same socket to handle requests and notifications. To fix existing applications relying on the old notification behavior, set the portid and sequence number in the notification only if the request included the NLM_F_ECHO flag. This restores the old behavior for applications not using it, but allows unicasted notifications for others. Fixes: f3a63cce1b4f ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link") Fixes: d88e136cab37 ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_newlink_create") Signed-off-by: Martin Willi Acked-by: Guillaume Nault Acked-by: Hangbin Liu Link: https://lore.kernel.org/r/20230411074319.24133-1-martin@strongswan.org Signed-off-by: Jakub Kicinski

net: openvswitch: fix race on port output

2023-04-08T02:42:53Z

assume the following setup on a single machine: 1. An openvswitch instance with one bridge and default flows 2. two network namespaces "server" and "client" 3. two ovs interfaces "server" and "client" on the bridge 4. for each ovs interface a veth pair with a matching name and 32 rx and tx queues 5. move the ends of the veth pairs to the respective network namespaces 6. assign ip addresses to each of the veth ends in the namespaces (needs to be the same subnet) 7. start some http server on the server network namespace 8. test if a client in the client namespace can reach the http server when following the actions below the host has a chance of getting a cpu stuck in a infinite loop: 1. send a large amount of parallel requests to the http server (around 3000 curls should work) 2. in parallel delete the network namespace (do not delete interfaces or stop the server, just kill the namespace) there is a low chance that this will cause the below kernel cpu stuck message. If this does not happen just retry. Below there is also the output of bpftrace for the functions mentioned in the output. The series of events happening here is: 1. the network namespace is deleted calling `unregister_netdevice_many_notify` somewhere in the process 2. this sets first `NETREG_UNREGISTERING` on both ends of the veth and then runs `synchronize_net` 3. it then calls `call_netdevice_notifiers` with `NETDEV_UNREGISTER` 4. this is then handled by `dp_device_event` which calls `ovs_netdev_detach_dev` (if a vport is found, which is the case for the veth interface attached to ovs) 5. this removes the rx_handlers of the device but does not prevent packages to be sent to the device 6. `dp_device_event` then queues the vport deletion to work in background as a ovs_lock is needed that we do not hold in the unregistration path 7. `unregister_netdevice_many_notify` continues to call `netdev_unregister_kobject` which sets `real_num_tx_queues` to 0 8. port deletion continues (but details are not relevant for this issue) 9. at some future point the background task deletes the vport If after 7. but before 9. a packet is send to the ovs vport (which is not deleted at this point in time) which forwards it to the `dev_queue_xmit` flow even though the device is unregistering. In `skb_tx_hash` (which is called in the `dev_queue_xmit`) path there is a while loop (if the packet has a rx_queue recorded) that is infinite if `dev->real_num_tx_queues` is zero. To prevent this from happening we update `do_output` to handle devices without carrier the same as if the device is not found (which would be the code path after 9. is done). Additionally we now produce a warning in `skb_tx_hash` if we will hit the infinite loop. bpftrace (first word is function name): __dev_queue_xmit server: real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1 netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1 dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 2, reg_state: 1 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 6, reg_state: 2 ovs_netdev_detach_dev server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, reg_state: 2 netdev_rx_handler_unregister server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 netdev_rx_handler_unregister ret server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2 dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 27, reg_state: 2 dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 22, reg_state: 2 dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 18, reg_state: 2 netdev_unregister_kobject: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024 synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024 ovs_vport_send server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2 __dev_queue_xmit server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2 netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2 broken device server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024 ovs_dp_detach_port server: real_num_tx_queues: 0 cpu 9, pid: 9124, tid: 9124, reg_state: 2 synchronize_rcu_expedited: cpu 9, pid: 33604, tid: 33604 stuck message: watchdog: BUG: soft lockup - CPU#5 stuck for 26s! [curl:1929279] Modules linked in: veth pktgen bridge stp llc ip_set_hash_net nft_counter xt_set nft_compat nf_tables ip_set_hash_ip ip_set nfnetlink_cttimeout nfnetlink openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 tls binfmt_misc nls_iso8859_1 input_leds joydev serio_raw dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua sch_fq_codel drm efi_pstore virtio_rng ip_tables x_tables autofs4 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel virtio_net ahci net_failover crypto_simd cryptd psmouse libahci virtio_blk failover CPU: 5 PID: 1929279 Comm: curl Not tainted 5.15.0-67-generic #74-Ubuntu Hardware name: OpenStack Foundation OpenStack Nova, BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:netdev_pick_tx+0xf1/0x320 Code: 00 00 8d 48 ff 0f b7 c1 66 39 ca 0f 86 e9 01 00 00 45 0f b7 ff 41 39 c7 0f 87 5b 01 00 00 44 29 f8 41 39 c7 0f 87 4f 01 00 00 f2 0f 1f 44 00 00 49 8b 94 24 28 04 00 00 48 85 d2 0f 84 53 01 RSP: 0018:ffffb78b40298820 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff9c8773adc2e0 RCX: 000000000000083f RDX: 0000000000000000 RSI: ffff9c8773adc2e0 RDI: ffff9c870a25e000 RBP: ffffb78b40298858 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9c870a25e000 R13: ffff9c870a25e000 R14: ffff9c87fe043480 R15: 0000000000000000 FS: 00007f7b80008f00(0000) GS:ffff9c8e5f740000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7b80f6a0b0 CR3: 0000000329d66000 CR4: 0000000000350ee0 Call Trace: netdev_core_pick_tx+0xa4/0xb0 __dev_queue_xmit+0xf8/0x510 ? __bpf_prog_exit+0x1e/0x30 dev_queue_xmit+0x10/0x20 ovs_vport_send+0xad/0x170 [openvswitch] do_output+0x59/0x180 [openvswitch] do_execute_actions+0xa80/0xaa0 [openvswitch] ? kfree+0x1/0x250 ? kfree+0x1/0x250 ? kprobe_perf_func+0x4f/0x2b0 ? flow_lookup.constprop.0+0x5c/0x110 [openvswitch] ovs_execute_actions+0x4c/0x120 [openvswitch] ovs_dp_process_packet+0xa1/0x200 [openvswitch] ? ovs_ct_update_key.isra.0+0xa8/0x120 [openvswitch] ? ovs_ct_fill_key+0x1d/0x30 [openvswitch] ? ovs_flow_key_extract+0x2db/0x350 [openvswitch] ovs_vport_receive+0x77/0xd0 [openvswitch] ? __htab_map_lookup_elem+0x4e/0x60 ? bpf_prog_680e8aff8547aec1_kfree+0x3b/0x714 ? trace_call_bpf+0xc8/0x150 ? kfree+0x1/0x250 ? kfree+0x1/0x250 ? kprobe_perf_func+0x4f/0x2b0 ? kprobe_perf_func+0x4f/0x2b0 ? __mod_memcg_lruvec_state+0x63/0xe0 netdev_port_receive+0xc4/0x180 [openvswitch] ? netdev_port_receive+0x180/0x180 [openvswitch] netdev_frame_hook+0x1f/0x40 [openvswitch] __netif_receive_skb_core.constprop.0+0x23d/0xf00 __netif_receive_skb_one_core+0x3f/0xa0 __netif_receive_skb+0x15/0x60 process_backlog+0x9e/0x170 __napi_poll+0x33/0x180 net_rx_action+0x126/0x280 ? ttwu_do_activate+0x72/0xf0 __do_softirq+0xd9/0x2e7 ? rcu_report_exp_cpu_mult+0x1b0/0x1b0 do_softirq+0x7d/0xb0 __local_bh_enable_ip+0x54/0x60 ip_finish_output2+0x191/0x460 __ip_finish_output+0xb7/0x180 ip_finish_output+0x2e/0xc0 ip_output+0x78/0x100 ? __ip_finish_output+0x180/0x180 ip_local_out+0x5e/0x70 __ip_queue_xmit+0x184/0x440 ? tcp_syn_options+0x1f9/0x300 ip_queue_xmit+0x15/0x20 __tcp_transmit_skb+0x910/0x9c0 ? __mod_memcg_state+0x44/0xa0 tcp_connect+0x437/0x4e0 ? ktime_get_with_offset+0x60/0xf0 tcp_v4_connect+0x436/0x530 __inet_stream_connect+0xd4/0x3a0 ? kprobe_perf_func+0x4f/0x2b0 ? aa_sk_perm+0x43/0x1c0 inet_stream_connect+0x3b/0x60 __sys_connect_file+0x63/0x70 __sys_connect+0xa6/0xd0 ? setfl+0x108/0x170 ? do_fcntl+0xe8/0x5a0 __x64_sys_connect+0x18/0x20 do_syscall_64+0x5c/0xc0 ? __x64_sys_fcntl+0xa9/0xd0 ? exit_to_user_mode_prepare+0x37/0xb0 ? syscall_exit_to_user_mode+0x27/0x50 ? do_syscall_64+0x69/0xc0 ? __sys_setsockopt+0xea/0x1e0 ? exit_to_user_mode_prepare+0x37/0xb0 ? syscall_exit_to_user_mode+0x27/0x50 ? __x64_sys_setsockopt+0x1f/0x30 ? do_syscall_64+0x69/0xc0 ? irqentry_exit+0x1d/0x30 ? exc_page_fault+0x89/0x170 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f7b8101c6a7 Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 18 89 54 24 0c 48 89 34 24 89 RSP: 002b:00007ffffd6b2198 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b8101c6a7 RDX: 0000000000000010 RSI: 00007ffffd6b2360 RDI: 0000000000000005 RBP: 0000561f1370d560 R08: 00002795ad21d1ac R09: 0030312e302e302e R10: 00007ffffd73f080 R11: 0000000000000246 R12: 0000561f1370c410 R13: 0000000000000000 R14: 0000000000000005 R15: 0000000000000000 Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action") Co-developed-by: Luca Czesla Signed-off-by: Luca Czesla Signed-off-by: Felix Huettner Reviewed-by: Eric Dumazet Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/ZC0pBXBAgh7c76CA@kernel-bug-kernel-bug Signed-off-by: Jakub Kicinski

net: fix __dev_kfree_skb_any() vs drop monitor

2023-02-24T11:02:07Z

dev_kfree_skb() is aliased to consume_skb(). When a driver is dropping a packet by calling dev_kfree_skb_any() we should propagate the drop reason instead of pretending the packet was consumed. Note: Now we have enum skb_drop_reason we could remove enum skb_free_reason (for linux-6.4) v2: added an unlikely(), suggested by Yunsheng Lin. Fixes: e6247027e517 ("net: introduce dev_consume_skb_any()") Signed-off-by: Eric Dumazet Cc: Yunsheng Lin Reviewed-by: Yunsheng Lin Signed-off-by: David S. Miller

net: add location to trace_consume_skb()

2023-02-20T08:28:49Z

kfree_skb() includes the location, it makes sense to add it to consume_skb() as well. After patch: taskd_EventMana 8602 [004] 420.406239: skb:consume_skb: skbaddr=0xffff893a4a6d0500 location=unix_stream_read_generic swapper 0 [011] 422.732607: skb:consume_skb: skbaddr=0xffff89597f68cee0 location=mlx4_en_free_tx_desc discipline 9141 [043] 423.065653: skb:consume_skb: skbaddr=0xffff893a487e9c00 location=skb_consume_udp swapper 0 [010] 423.073166: skb:consume_skb: skbaddr=0xffff8949ce9cdb00 location=icmpv6_rcv borglet 8672 [014] 425.628256: skb:consume_skb: skbaddr=0xffff8949c42e9400 location=netlink_dump swapper 0 [028] 426.263317: skb:consume_skb: skbaddr=0xffff893b1589dce0 location=net_rx_action wget 14339 [009] 426.686380: skb:consume_skb: skbaddr=0xffff893a51b552e0 location=tcp_rcv_state_process Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

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

2023-02-17T11:06:39Z

Some of the devlink bits were tricky, but I think I got it right. Signed-off-by: David S. Miller

devlink: Fix netdev notifier chain corruption

2023-02-16T10:53:47Z

Cited commit changed devlink to register its netdev notifier block on the global netdev notifier chain instead of on the per network namespace one. However, when changing the network namespace of the devlink instance, devlink still tries to unregister its notifier block from the chain of the old namespace and register it on the chain of the new namespace. This results in corruption of the notifier chains, as the same notifier block is registered on two different chains: The global one and the per network namespace one. In turn, this causes other problems such as the inability to dismantle namespaces due to netdev reference count issues. Fix by preventing devlink from moving its notifier block between namespaces. Reproducer: # echo "10 1" > /sys/bus/netdevsim/new_device # ip netns add test123 # devlink dev reload netdevsim/netdevsim10 netns test123 # ip netns del test123 [ 71.935619] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 71.938348] leaked reference. Fixes: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Reviewed-by: Jacob Keller Reviewed-by: Jakub Kicinski Link: https://lore.kernel.org/r/20230215073139.1360108-1-idosch@nvidia.com Signed-off-by: Paolo Abeni

net/core: refactor promiscuous mode message

2023-02-16T09:11:14Z

The kernel stack can be more consistent by printing the IFF_PROMISC aka promiscuous enable/disable messages with the standard netdev_info message which can include bus and driver info as well as the device. typical command usage from user space looks like: ip link set eth0 promisc But lots of utilities such as bridge, tcpdump, etc put the interface into promiscuous mode. old message: [ 406.034418] device eth0 entered promiscuous mode [ 408.424703] device eth0 left promiscuous mode new message: [ 406.034431] ice 0000:17:00.0 eth0: entered promiscuous mode [ 408.424715] ice 0000:17:00.0 eth0: left promiscuous mode Signed-off-by: Jesse Brandeburg Signed-off-by: Paolo Abeni

net/core: print message for allmulticast

2023-02-16T09:11:14Z

When the user sets or clears the IFF_ALLMULTI flag in the netdev, there are no log messages printed to the kernel log to indicate anything happened. This is inexplicably different from most other dev->flags changes, and could suprise the user. Typically this occurs from user-space when a user: ip link set eth0 allmulticast However, other devices like bridge set allmulticast as well, and many other flows might trigger entry into allmulticast as well. The new message uses the standard netdev_info print and looks like: [ 413.246110] ixgbe 0000:17:00.0 eth0: entered allmulticast mode [ 415.977184] ixgbe 0000:17:00.0 eth0: left allmulticast mode Signed-off-by: Jesse Brandeburg Signed-off-by: Paolo Abeni

net: Fix unwanted sign extension in netdev_stats_to_stats64()

2023-02-13T09:53:25Z

When converting net_device_stats to rtnl_link_stats64 sign extension is triggered on ILP32 machines as 6c1c509778 changed the previous "ulong -> u64" conversion to "long -> u64" by accessing the net_device_stats fields through a (signed) atomic_long_t. This causes for example the received bytes counter to jump to 16EiB after having received 2^31 bytes. Casting the atomic value to "unsigned long" beforehand converting it into u64 avoids this. Fixes: 6c1c5097781f ("net: add atomic_long_t to net_device_stats fields") Signed-off-by: Felix Riemann Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller

Daniel Borkmann says:

2023-02-11T01:51:27Z

==================== pull-request: bpf-next 2023-02-11 We've added 96 non-merge commits during the last 14 day(s) which contain a total of 152 files changed, 4884 insertions(+), 962 deletions(-). There is a minor conflict in drivers/net/ethernet/intel/ice/ice_main.c between commit 5b246e533d01 ("ice: split probe into smaller functions") from the net-next tree and commit 66c0e13ad236 ("drivers: net: turn on XDP features") from the bpf-next tree. Remove the hunk given ice_cfg_netdev() is otherwise there a 2nd time, and add XDP features to the existing ice_cfg_netdev() one: [...] ice_set_netdev_features(netdev); netdev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT | NETDEV_XDP_ACT_XSK_ZEROCOPY; ice_set_ops(netdev); [...] Stephen's merge conflict mail: https://lore.kernel.org/bpf/20230207101951.21a114fa@canb.auug.org.au/ The main changes are: 1) Add support for BPF trampoline on s390x which finally allows to remove many test cases from the BPF CI's DENYLIST.s390x, from Ilya Leoshkevich. 2) Add multi-buffer XDP support to ice driver, from Maciej Fijalkowski. 3) Add capability to export the XDP features supported by the NIC. Along with that, add a XDP compliance test tool, from Lorenzo Bianconi & Marek Majtyka. 4) Add __bpf_kfunc tag for marking kernel functions as kfuncs, from David Vernet. 5) Add a deep dive documentation about the verifier's register liveness tracking algorithm, from Eduard Zingerman. 6) Fix and follow-up cleanups for resolve_btfids to be compiled as a host program to avoid cross compile issues, from Jiri Olsa & Ian Rogers. 7) Batch of fixes to the BPF selftest for xdp_hw_metadata which resulted when testing on different NICs, from Jesper Dangaard Brouer. 8) Fix libbpf to better detect kernel version code on Debian, from Hao Xiang. 9) Extend libbpf to add an option for when the perf buffer should wake up, from Jon Doron. 10) Follow-up fix on xdp_metadata selftest to just consume on TX completion, from Stanislav Fomichev. 11) Extend the kfuncs.rst document with description on kfunc lifecycle & stability expectations, from David Vernet. 12) Fix bpftool prog profile to skip attaching to offline CPUs, from Tonghao Zhang. ==================== Link: https://lore.kernel.org/r/20230211002037.8489-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski