erspan1: entered allmulticast mode bond3: (slave erspan1): making interface the new active one erspan1: entered promiscuous mode ============================================ WARNING: possible recursive locking detected syzkaller #0 Tainted: G L -------------------------------------------- syz.4.915/8403 is trying to acquire lock: ffff888059ef8958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] ffff888059ef8958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4809 [inline] ffff888059ef8958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3b5/0xc70 net/sched/sch_generic.c:370 but task is already holding lock: ffff8880333cb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] ffff8880333cb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4809 [inline] ffff8880333cb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3b5/0xc70 net/sched/sch_generic.c:370 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&qdisc_xmit_lock_key#4); lock(&qdisc_xmit_lock_key#4); *** DEADLOCK *** May be due to missing lock nesting notation 9 locks held by syz.4.915/8403: #0: ffffffff91242de8 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #0: ffffffff91242de8 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #0: ffffffff91242de8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x113/0x2c0 net/core/rtnetlink.c:574 #1: ffffffff90a9c7c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff90a9c7c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff90a9c7c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8bb/0x2380 net/core/rtnetlink.c:4158 #2: ffffffff8ebe6120 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #2: ffffffff8ebe6120 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:893 [inline] #2: ffffffff8ebe6120 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x296/0x4970 net/core/dev.c:4796 #3: ffff88803048a228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:354 [inline] #3: ffff88803048a228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:205 [inline] #3: ffff88803048a228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4201 [inline] #3: ffff88803048a228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x2504/0x4970 net/core/dev.c:4836 #4: ffff8880333cb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] #4: ffff8880333cb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4809 [inline] #4: ffff8880333cb158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3b5/0xc70 net/sched/sch_generic.c:370 #5: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #5: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: ip_output+0xb3/0xc10 net/ipv4/ip_output.c:432 #6: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #6: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #6: ffffffff8ebe6180 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x356/0x2400 net/ipv4/ip_output.c:229 #7: ffffffff8ebe6120 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #7: ffffffff8ebe6120 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:893 [inline] #7: ffffffff8ebe6120 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x296/0x4970 net/core/dev.c:4796 #8: ffff88802acd1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:354 [inline] #8: ffff88802acd1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:205 [inline] #8: ffff88802acd1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4201 [inline] #8: ffff88802acd1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x2504/0x4970 net/core/dev.c:4836 stack backtrace: CPU: 0 UID: 0 PID: 8403 Comm: syz.4.915 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_deadlock_bug.cold+0xbd/0xca kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x1256/0x1a40 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] __netif_tx_lock include/linux/netdevice.h:4809 [inline] sch_direct_xmit+0x3b5/0xc70 net/sched/sch_generic.c:370 __dev_xmit_skb net/core/dev.c:4214 [inline] __dev_queue_xmit+0x27ac/0x4970 net/core/dev.c:4836 dev_queue_xmit include/linux/netdevice.h:3446 [inline] neigh_resolve_output net/core/neighbour.c:1616 [inline] neigh_resolve_output+0x51f/0x8f0 net/core/neighbour.c:1596 neigh_output include/net/neighbour.h:560 [inline] ip_finish_output2+0x851/0x2400 net/ipv4/ip_output.c:236 __ip_finish_output.part.0+0x444/0x6f0 net/ipv4/ip_output.c:314 __ip_finish_output net/ipv4/ip_output.c:302 [inline] ip_finish_output net/ipv4/ip_output.c:324 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x39b/0xc10 net/ipv4/ip_output.c:437 dst_output include/net/dst.h:470 [inline] ip_local_out+0x193/0x1f0 net/ipv4/ip_output.c:131 iptunnel_xmit+0x722/0xd20 net/ipv4/ip_tunnel_core.c:97 ip_tunnel_xmit+0x1b91/0x3210 net/ipv4/ip_tunnel.c:848 __gre_xmit+0x820/0xb20 net/ipv4/ip_gre.c:491 erspan_xmit+0x55a/0x1ec0 net/ipv4/ip_gre.c:750 __netdev_start_xmit include/linux/netdevice.h:5400 [inline] netdev_start_xmit include/linux/netdevice.h:5409 [inline] xmit_one net/core/dev.c:3889 [inline] dev_hard_start_xmit+0x121/0x760 net/core/dev.c:3905 sch_direct_xmit+0x1b2/0xc70 net/sched/sch_generic.c:372 __dev_xmit_skb net/core/dev.c:4214 [inline] __dev_queue_xmit+0x27ac/0x4970 net/core/dev.c:4836 dev_queue_xmit include/linux/netdevice.h:3446 [inline] alb_send_lp_vid+0x31e/0x540 drivers/net/bonding/bond_alb.c:949 alb_send_learning_packets+0xe0/0x2f0 drivers/net/bonding/bond_alb.c:1012 alb_fasten_mac_swap+0x47f/0xa90 drivers/net/bonding/bond_alb.c:1076 bond_alb_handle_active_change+0x634/0x10b0 drivers/net/bonding/bond_alb.c:1774 bond_change_active_slave+0x160c/0x2ed0 drivers/net/bonding/bond_main.c:1309 bond_select_active_slave+0x3f5/0xca0 drivers/net/bonding/bond_main.c:1379 bond_enslave+0x4513/0x5cb0 drivers/net/bonding/bond_main.c:2298 do_set_master+0x40f/0x730 net/core/rtnetlink.c:3020 rtnl_newlink_create net/core/rtnetlink.c:3927 [inline] __rtnl_newlink net/core/rtnetlink.c:4044 [inline] rtnl_newlink+0x15c7/0x2380 net/core/rtnetlink.c:4159 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738 __sys_sendmsg+0x160/0x210 net/socket.c:2770 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa8b579de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa8b39d5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa8b5a26090 RCX: 00007fa8b579de99 RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fa8b5833eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa8b5a26128 R14: 00007fa8b5a26090 R15: 00007ffc7ed12fc8 bond3: (slave erspan1): Enslaving as an active interface with an up link syz.4.915 (8403) used greatest stack depth: 19824 bytes left