kernel.git/drivers/net/bonding, branch linux-6.1.y

bonding: alb: fix UAF in rlb_arp_recv during bond up/down

2026-03-04T12:20:08Z

[ Upstream commit e6834a4c474697df23ab9948fd3577b26bf48656 ] The ALB RX path may access rx_hashtbl concurrently with bond teardown. During rapid bond up/down cycles, rlb_deinitialize() frees rx_hashtbl while RX handlers are still running, leading to a null pointer dereference detected by KASAN. However, the root cause is that rlb_arp_recv() can still be accessed after setting recv_probe to NULL, which is actually a use-after-free (UAF) issue. That is the reason for using the referenced commit in the Fixes tag. [ 214.174138] Oops: general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] SMP KASAN PTI [ 214.186478] KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] [ 214.194933] CPU: 30 UID: 0 PID: 2375 Comm: ping Kdump: loaded Not tainted 6.19.0-rc8+ #2 PREEMPT(voluntary) [ 214.205907] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.14.0 01/14/2022 [ 214.214357] RIP: 0010:rlb_arp_recv+0x505/0xab0 [bonding] [ 214.220320] Code: 0f 85 2b 05 00 00 48 b8 00 00 00 00 00 fc ff df 40 0f b6 ed 48 c1 e5 06 49 03 ad 78 01 00 00 48 8d 7d 28 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 12 05 00 00 80 7d 28 00 0f 84 8c 00 [ 214.241280] RSP: 0018:ffffc900073d8870 EFLAGS: 00010206 [ 214.247116] RAX: dffffc0000000000 RBX: ffff888168556822 RCX: ffff88816855681e [ 214.255082] RDX: 000000000000001d RSI: dffffc0000000000 RDI: 00000000000000e8 [ 214.263048] RBP: 00000000000000c0 R08: 0000000000000002 R09: ffffed11192021c8 [ 214.271013] R10: ffff8888c9010e43 R11: 0000000000000001 R12: 1ffff92000e7b119 [ 214.278978] R13: ffff8888c9010e00 R14: ffff888168556822 R15: ffff888168556810 [ 214.286943] FS: 00007f85d2d9cb80(0000) GS:ffff88886ccb3000(0000) knlGS:0000000000000000 [ 214.295966] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 214.302380] CR2: 00007f0d047b5e34 CR3: 00000008a1c2e002 CR4: 00000000001726f0 [ 214.310347] Call Trace: [ 214.313070] [ 214.315318] ? __pfx_rlb_arp_recv+0x10/0x10 [bonding] [ 214.320975] bond_handle_frame+0x166/0xb60 [bonding] [ 214.326537] ? __pfx_bond_handle_frame+0x10/0x10 [bonding] [ 214.332680] __netif_receive_skb_core.constprop.0+0x576/0x2710 [ 214.339199] ? __pfx_arp_process+0x10/0x10 [ 214.343775] ? sched_balance_find_src_group+0x98/0x630 [ 214.349513] ? __pfx___netif_receive_skb_core.constprop.0+0x10/0x10 [ 214.356513] ? arp_rcv+0x307/0x690 [ 214.360311] ? __pfx_arp_rcv+0x10/0x10 [ 214.364499] ? __lock_acquire+0x58c/0xbd0 [ 214.368975] __netif_receive_skb_one_core+0xae/0x1b0 [ 214.374518] ? __pfx___netif_receive_skb_one_core+0x10/0x10 [ 214.380743] ? lock_acquire+0x10b/0x140 [ 214.385026] process_backlog+0x3f1/0x13a0 [ 214.389502] ? process_backlog+0x3aa/0x13a0 [ 214.394174] __napi_poll.constprop.0+0x9f/0x370 [ 214.399233] net_rx_action+0x8c1/0xe60 [ 214.403423] ? __pfx_net_rx_action+0x10/0x10 [ 214.408193] ? lock_acquire.part.0+0xbd/0x260 [ 214.413058] ? sched_clock_cpu+0x6c/0x540 [ 214.417540] ? mark_held_locks+0x40/0x70 [ 214.421920] handle_softirqs+0x1fd/0x860 [ 214.426302] ? __pfx_handle_softirqs+0x10/0x10 [ 214.431264] ? __neigh_event_send+0x2d6/0xf50 [ 214.436131] do_softirq+0xb1/0xf0 [ 214.439830] The issue is reproducible by repeatedly running ip link set bond0 up/down while receiving ARP messages, where rlb_arp_recv() can race with rlb_deinitialize() and dereference a freed rx_hashtbl entry. Fix this by setting recv_probe to NULL and then calling synchronize_net() to wait for any concurrent RX processing to finish. This ensures that no RX handler can access rx_hashtbl after it is freed in bond_alb_deinitialize(). Reported-by: Liang Li Fixes: 3aba891dde38 ("bonding: move processing of recv handlers into handle_frame()") Reviewed-by: Nikolay Aleksandrov Acked-by: Jay Vosburgh Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20260218060919.101574-1-liuhangbin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

bonding: only set speed/duplex to unknown, if getting speed failed

2026-03-04T12:19:43Z

[ Upstream commit 48dec8d88af96039a4a17b8c2f148f2a4066e195 ] bond_update_speed_duplex() first set speed/duplex to unknown and then asks slave driver for current speed/duplex. Since getting speed/duplex might take longer there is a race, where this false state is visible by /proc/net/bonding. With commit 691b2bf14946 ("bonding: update port speed when getting bond speed") this race gets more visible, if user space is calling ethtool on a regular base. Fix this by only setting speed/duplex to unknown, if link speed is really unknown/unusable. Fixes: 98f41f694f46 ("bonding:update speed/duplex for NETDEV_CHANGE") Signed-off-by: Thomas Bogendoerfer Acked-by: Jay Vosburgh Reviewed-by: Nikolay Aleksandrov Reviewed-by: Hangbin Liu Link: https://patch.msgid.link/20260203141153.51581-1-tbogendoerfer@suse.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

bonding: annotate data-races around slave->last_rx

2026-02-06T15:44:15Z

[ Upstream commit f6c3665b6dc53c3ab7d31b585446a953a74340ef ] slave->last_rx and slave->target_last_arp_rx[...] can be read and written locklessly. Add READ_ONCE() and WRITE_ONCE() annotations. syzbot reported: BUG: KCSAN: data-race in bond_rcv_validate / bond_rcv_validate write to 0xffff888149f0d428 of 8 bytes by interrupt on cpu 1: bond_rcv_validate+0x202/0x7a0 drivers/net/bonding/bond_main.c:3335 bond_handle_frame+0xde/0x5e0 drivers/net/bonding/bond_main.c:1533 __netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6039 __netif_receive_skb_one_core net/core/dev.c:6150 [inline] __netif_receive_skb+0x59/0x270 net/core/dev.c:6265 netif_receive_skb_internal net/core/dev.c:6351 [inline] netif_receive_skb+0x4b/0x2d0 net/core/dev.c:6410 ... write to 0xffff888149f0d428 of 8 bytes by interrupt on cpu 0: bond_rcv_validate+0x202/0x7a0 drivers/net/bonding/bond_main.c:3335 bond_handle_frame+0xde/0x5e0 drivers/net/bonding/bond_main.c:1533 __netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6039 __netif_receive_skb_one_core net/core/dev.c:6150 [inline] __netif_receive_skb+0x59/0x270 net/core/dev.c:6265 netif_receive_skb_internal net/core/dev.c:6351 [inline] netif_receive_skb+0x4b/0x2d0 net/core/dev.c:6410 br_netif_receive_skb net/bridge/br_input.c:30 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] ... value changed: 0x0000000100005365 -> 0x0000000100005366 Fixes: f5b2b966f032 ("[PATCH] bonding: Validate probe replies in ARP monitor") Signed-off-by: Eric Dumazet Reported-by: syzbot Link: https://patch.msgid.link/20260122162914.2299312-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

bonding: provide a net pointer to __skb_flow_dissect()

2026-02-06T15:44:10Z

[ Upstream commit 5f9b329096596b7e53e07d041d7fca4cbe1be752 ] After 3cbf4ffba5ee ("net: plumb network namespace into __skb_flow_dissect") we have to provide a net pointer to __skb_flow_dissect(), either via skb->dev, skb->sk, or a user provided pointer. In the following case, syzbot was able to cook a bare skb. WARNING: net/core/flow_dissector.c:1131 at __skb_flow_dissect+0xb57/0x68b0 net/core/flow_dissector.c:1131, CPU#1: syz.2.1418/11053 Call Trace: bond_flow_dissect drivers/net/bonding/bond_main.c:4093 [inline] __bond_xmit_hash+0x2d7/0xba0 drivers/net/bonding/bond_main.c:4157 bond_xmit_hash_xdp drivers/net/bonding/bond_main.c:4208 [inline] bond_xdp_xmit_3ad_xor_slave_get drivers/net/bonding/bond_main.c:5139 [inline] bond_xdp_get_xmit_slave+0x1fd/0x710 drivers/net/bonding/bond_main.c:5515 xdp_master_redirect+0x13f/0x2c0 net/core/filter.c:4388 bpf_prog_run_xdp include/net/xdp.h:700 [inline] bpf_test_run+0x6b2/0x7d0 net/bpf/test_run.c:421 bpf_prog_test_run_xdp+0x795/0x10e0 net/bpf/test_run.c:1390 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4703 __sys_bpf+0x562/0x860 kernel/bpf/syscall.c:6182 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline] __se_sys_bpf kernel/bpf/syscall.c:6272 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6272 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 Fixes: 58deb77cc52d ("bonding: balance ICMP echoes in layer3+4 mode") Reported-by: syzbot+c46409299c70a221415e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/696faa23.050a0220.4cb9c.001f.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Matteo Croce Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20260120161744.1893263-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

bonding: limit BOND_MODE_8023AD to Ethernet devices

2026-02-06T15:44:05Z

[ Upstream commit c84fcb79e5dbde0b8d5aeeaf04282d2149aebcf6 ] BOND_MODE_8023AD makes sense for ARPHRD_ETHER only. syzbot reported: BUG: KASAN: global-out-of-bounds in __hw_addr_create net/core/dev_addr_lists.c:63 [inline] BUG: KASAN: global-out-of-bounds in __hw_addr_add_ex+0x25d/0x760 net/core/dev_addr_lists.c:118 Read of size 16 at addr ffffffff8bf94040 by task syz.1.3580/19497 CPU: 1 UID: 0 PID: 19497 Comm: syz.1.3580 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 __hw_addr_create net/core/dev_addr_lists.c:63 [inline] __hw_addr_add_ex+0x25d/0x760 net/core/dev_addr_lists.c:118 __dev_mc_add net/core/dev_addr_lists.c:868 [inline] dev_mc_add+0xa1/0x120 net/core/dev_addr_lists.c:886 bond_enslave+0x2b8b/0x3ac0 drivers/net/bonding/bond_main.c:2180 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3165 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg+0x164/0x220 net/socket.c:2678 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x1dc/0x560 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the variable: lacpdu_mcast_addr+0x0/0x40 Fixes: 872254dd6b1f ("net/bonding: Enable bonding to enslave non ARPHRD_ETHER") Reported-by: syzbot+9c081b17773615f24672@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6966946b.a70a0220.245e30.0002.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Andrew Lunn Acked-by: Jay Vosburgh Link: https://patch.msgid.link/20260113191201.3970737-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: bonding: fix possible peer notify event loss or dup issue

2025-10-29T13:04:37Z

commit 10843e1492e474c02b91314963161731fa92af91 upstream. If the send_peer_notif counter and the peer event notify are not synchronized. It may cause problems such as the loss or dup of peer notify event. Before this patch: - If should_notify_peers is true and the lock for send_peer_notif-- fails, peer event may be sent again in next mii_monitor loop, because should_notify_peers is still true. - If should_notify_peers is true and the lock for send_peer_notif-- succeeded, but the lock for peer event fails, the peer event will be lost. This patch locks the RTNL for send_peer_notif, events, and commit simultaneously. Fixes: 07a4ddec3ce9 ("bonding: add an option to specify a delay between peer notifications") Cc: Jay Vosburgh Cc: Andrew Lunn Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Hangbin Liu Cc: Nikolay Aleksandrov Cc: Vincent Bernat Cc: Signed-off-by: Tonghao Zhang Acked-by: Jay Vosburgh Link: https://patch.msgid.link/20251021050933.46412-1-tonghao@bamaicloud.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

bonding: don't set oif to bond dev when getting NS target destination

2025-09-25T08:58:51Z

[ Upstream commit a8ba87f04ca9cdec06776ce92dce1395026dc3bb ] Unlike IPv4, IPv6 routing strictly requires the source address to be valid on the outgoing interface. If the NS target is set to a remote VLAN interface, and the source address is also configured on a VLAN over a bond interface, setting the oif to the bond device will fail to retrieve the correct destination route. Fix this by not setting the oif to the bond device when retrieving the NS target destination. This allows the correct destination device (the VLAN interface) to be determined, so that bond_verify_device_path can return the proper VLAN tags for sending NS messages. Reported-by: David Wilder Closes: https://lore.kernel.org/netdev/aGOKggdfjv0cApTO@fedora/ Suggested-by: Jay Vosburgh Tested-by: David Wilder Acked-by: Jay Vosburgh Fixes: 4e24be018eb9 ("bonding: add new parameter ns_targets") Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20250916080127.430626-1-liuhangbin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

bonding: send LACPDUs periodically in passive mode after receiving partner's LACPDU

2025-08-28T14:26:18Z

[ Upstream commit 0599640a21e98f0d6a3e9ff85c0a687c90a8103b ] When `lacp_active` is set to `off`, the bond operates in passive mode, meaning it only "speaks when spoken to." However, the current kernel implementation only sends an LACPDU in response when the partner's state changes. As a result, once LACP negotiation succeeds, the actor stops sending LACPDUs until the partner times out and sends an "expired" LACPDU. This causes continuous LACP state flapping. According to IEEE 802.1AX-2014, 6.4.13 Periodic Transmission machine. The values of Partner_Oper_Port_State.LACP_Activity and Actor_Oper_Port_State.LACP_Activity determine whether periodic transmissions take place. If either or both parameters are set to Active LACP, then periodic transmissions occur; if both are set to Passive LACP, then periodic transmissions do not occur. To comply with this, we remove the `!bond->params.lacp_active` check in `ad_periodic_machine()`. Instead, we initialize the actor's port's `LACP_STATE_LACP_ACTIVITY` state based on `lacp_active` setting. Additionally, we avoid setting the partner's state to `LACP_STATE_LACP_ACTIVITY` in the EXPIRED state, since we should not assume the partner is active by default. This ensures that in passive mode, the bond starts sending periodic LACPDUs after receiving one from the partner, and avoids flapping due to inactivity. Fixes: 3a755cd8b7c6 ("bonding: add new option lacp_active") Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20250815062000.22220-3-liuhangbin@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

bonding: Add independent control state machine

2025-08-28T14:26:18Z

[ Upstream commit 240fd405528bbf7fafa0559202ca7aa524c9cd96 ] Add support for the independent control state machine per IEEE 802.1AX-2008 5.4.15 in addition to the existing implementation of the coupled control state machine. Introduces two new states, AD_MUX_COLLECTING and AD_MUX_DISTRIBUTING in the LACP MUX state machine for separated handling of an initial Collecting state before the Collecting and Distributing state. This enables a port to be in a state where it can receive incoming packets while not still distributing. This is useful for reducing packet loss when a port begins distributing before its partner is able to collect. Added new functions such as bond_set_slave_tx_disabled_flags and bond_set_slave_rx_enabled_flags to precisely manage the port's collecting and distributing states. Previously, there was no dedicated method to disable TX while keeping RX enabled, which this patch addresses. Note that the regular flow process in the kernel's bonding driver remains unaffected by this patch. The extension requires explicit opt-in by the user (in order to ensure no disruptions for existing setups) via netlink support using the new bonding parameter coupled_control. The default value for coupled_control is set to 1 so as to preserve existing behaviour. Signed-off-by: Aahil Awatramani Reviewed-by: Hangbin Liu Link: https://lore.kernel.org/r/20240202175858.1573852-1-aahila@google.com Signed-off-by: Paolo Abeni Stable-dep-of: 0599640a21e9 ("bonding: send LACPDUs periodically in passive mode after receiving partner's LACPDU") Signed-off-by: Sasha Levin

bonding: update LACP activity flag after setting lacp_active

2025-08-28T14:26:18Z

[ Upstream commit b64d035f77b1f02ab449393342264b44950a75ae ] The port's actor_oper_port_state activity flag should be updated immediately after changing the lacp_active option to reflect the current mode correctly. Fixes: 3a755cd8b7c6 ("bonding: add new option lacp_active") Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20250815062000.22220-2-liuhangbin@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin