kernel.git/drivers/net/bonding, branch linux-6.12.y

bpf/bonding: reject vlan+srcmac xmit_hash_policy change when XDP is loaded

2026-03-13T16:20:41Z

[ Upstream commit 479d589b40b836442bbdadc3fdb37f001bb67f26 ] bond_option_mode_set() already rejects mode changes that would make a loaded XDP program incompatible via bond_xdp_check(). However, bond_option_xmit_hash_policy_set() has no such guard. For 802.3ad and balance-xor modes, bond_xdp_check() returns false when xmit_hash_policy is vlan+srcmac, because the 802.1q payload is usually absent due to hardware offload. This means a user can: 1. Attach a native XDP program to a bond in 802.3ad/balance-xor mode with a compatible xmit_hash_policy (e.g. layer2+3). 2. Change xmit_hash_policy to vlan+srcmac while XDP remains loaded. This leaves bond->xdp_prog set but bond_xdp_check() now returning false for the same device. When the bond is later destroyed, dev_xdp_uninstall() calls bond_xdp_set(dev, NULL, NULL) to remove the program, which hits the bond_xdp_check() guard and returns -EOPNOTSUPP, triggering: WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL)) Fix this by rejecting xmit_hash_policy changes to vlan+srcmac when an XDP program is loaded on a bond in 802.3ad or balance-xor mode. commit 39a0876d595b ("net, bonding: Disallow vlan+srcmac with XDP") introduced bond_xdp_check() which returns false for 802.3ad/balance-xor modes when xmit_hash_policy is vlan+srcmac. The check was wired into bond_xdp_set() to reject XDP attachment with an incompatible policy, but the symmetric path -- preventing xmit_hash_policy from being changed to an incompatible value after XDP is already loaded -- was left unguarded in bond_option_xmit_hash_policy_set(). Note: commit 094ee6017ea0 ("bonding: check xdp prog when set bond mode") later added a similar guard to bond_option_mode_set(), but bond_option_xmit_hash_policy_set() remained unprotected. Reported-by: syzbot+5a287bcdc08104bc3132@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6995aff6.050a0220.2eeac1.014e.GAE@google.com/T/ Fixes: 39a0876d595b ("net, bonding: Disallow vlan+srcmac with XDP") Signed-off-by: Jiayuan Chen Link: https://patch.msgid.link/20260226080306.98766-2-jiayuan.chen@linux.dev Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

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

2026-03-04T12:20:39Z

[ 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

2026-03-04T12:20:08Z

[ 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

2026-02-06T15:55:41Z

[ 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()

2026-01-30T09:28:43Z

[ 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

2026-01-30T09:28:38Z

[ 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

bonding: check xdp prog when set bond mode

2025-11-02T13:15:22Z

[ Upstream commit 094ee6017ea09c11d6af187935a949df32803ce0 ] Following operations can trigger a warning[1]: ip netns add ns1 ip netns exec ns1 ip link add bond0 type bond mode balance-rr ip netns exec ns1 ip link set dev bond0 xdp obj af_xdp_kern.o sec xdp ip netns exec ns1 ip link set bond0 type bond mode broadcast ip netns del ns1 When delete the namespace, dev_xdp_uninstall() is called to remove xdp program on bond dev, and bond_xdp_set() will check the bond mode. If bond mode is changed after attaching xdp program, the warning may occur. Some bond modes (broadcast, etc.) do not support native xdp. Set bond mode with xdp program attached is not good. Add check for xdp program when set bond mode. [1] ------------[ cut here ]------------ WARNING: CPU: 0 PID: 11 at net/core/dev.c:9912 unregister_netdevice_many_notify+0x8d9/0x930 Modules linked in: CPU: 0 UID: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.14.0-rc4 #107 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 Workqueue: netns cleanup_net RIP: 0010:unregister_netdevice_many_notify+0x8d9/0x930 Code: 00 00 48 c7 c6 6f e3 a2 82 48 c7 c7 d0 b3 96 82 e8 9c 10 3e ... RSP: 0018:ffffc90000063d80 EFLAGS: 00000282 RAX: 00000000ffffffa1 RBX: ffff888004959000 RCX: 00000000ffffdfff RDX: 0000000000000000 RSI: 00000000ffffffea RDI: ffffc90000063b48 RBP: ffffc90000063e28 R08: ffffffff82d39b28 R09: 0000000000009ffb R10: 0000000000000175 R11: ffffffff82d09b40 R12: ffff8880049598e8 R13: 0000000000000001 R14: dead000000000100 R15: ffffc90000045000 FS: 0000000000000000(0000) GS:ffff888007a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000d406b60 CR3: 000000000483e000 CR4: 00000000000006f0 Call Trace: ? __warn+0x83/0x130 ? unregister_netdevice_many_notify+0x8d9/0x930 ? report_bug+0x18e/0x1a0 ? handle_bug+0x54/0x90 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? unregister_netdevice_many_notify+0x8d9/0x930 ? bond_net_exit_batch_rtnl+0x5c/0x90 cleanup_net+0x237/0x3d0 process_one_work+0x163/0x390 worker_thread+0x293/0x3b0 ? __pfx_worker_thread+0x10/0x10 kthread+0xec/0x1e0 ? __pfx_kthread+0x10/0x10 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2f/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 ---[ end trace 0000000000000000 ]--- Fixes: 9e2ee5c7e7c3 ("net, bonding: Add XDP support to the bonding driver") Signed-off-by: Wang Liang Acked-by: Jussi Maki Reviewed-by: Nikolay Aleksandrov Reviewed-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20250321044852.1086551-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski Signed-off-by: Rajani Kantha <681739313@139.com> Signed-off-by: Greg Kroah-Hartman

bonding: return detailed error when loading native XDP fails

2025-11-02T13:15:22Z

[ Upstream commit 22ccb684c1cae37411450e6e86a379cd3c29cb8f ] Bonding only supports native XDP for specific modes, which can lead to confusion for users regarding why XDP loads successfully at times and fails at others. This patch enhances error handling by returning detailed error messages, providing users with clearer insights into the specific reasons for the failure when loading native XDP. Reviewed-by: Nikolay Aleksandrov Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Hangbin Liu Link: https://patch.msgid.link/20241021031211.814-2-liuhangbin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Rajani Kantha <681739313@139.com> Signed-off-by: Greg Kroah-Hartman

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

2025-10-29T13:08:55Z

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

2025-09-25T09:13:44Z

[ 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