bond3: entered allmulticast mode 8021q: adding VLAN 0 to HW filter on device bond3 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.3.7597/6563 is trying to acquire lock: ffff88807d4c2158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] ffff88807d4c2158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4746 [inline] ffff88807d4c2158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 but task is already holding lock: ffff88803ff8e958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] ffff88803ff8e958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4746 [inline] ffff88803ff8e958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 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 10 locks held by syz.3.7597/6563: #0: ffffffff90137648 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff90137648 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff90137648 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbd0048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbd0048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbd0048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4093 #2: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #2: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #2: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x277/0x3890 net/core/dev.c:4773 #3: ffff88807a925228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:353 [inline] #3: ffff88807a925228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #3: ffff88807a925228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4185 [inline] #3: ffff88807a925228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_queue_xmit+0x101c/0x3890 net/core/dev.c:4814 #4: ffff88803ff8e958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] #4: ffff88803ff8e958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4746 [inline] #4: ffff88803ff8e958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 #5: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #5: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #5: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450 net/ipv4/ip_output.c:433 #6: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #6: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #6: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x3c2/0x1070 net/ipv4/ip_output.c:230 #7: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #7: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #7: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x23/0x270 net/ipv4/arp.c:664 #8: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #8: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x277/0x3890 net/core/dev.c:4773 #9: ffff888057909228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:353 [inline] #9: ffff888057909228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #9: ffff888057909228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4185 [inline] #9: ffff888057909228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_queue_xmit+0x101c/0x3890 net/core/dev.c:4814 stack backtrace: CPU: 0 UID: 0 PID: 6563 Comm: syz.3.7597 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:341 [inline] __netif_tx_lock include/linux/netdevice.h:4746 [inline] sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:4198 [inline] __dev_queue_xmit+0x1550/0x3890 net/core/dev.c:4814 NF_HOOK+0x33a/0x3c0 include/linux/netfilter.h:-1 arp_xmit+0x16c/0x270 net/ipv4/arp.c:666 arp_solicit+0xbe0/0xe40 net/ipv4/arp.c:393 neigh_probe net/core/neighbour.c:1097 [inline] __neigh_event_send+0xf05/0x1530 net/core/neighbour.c:1277 neigh_event_send_probe include/net/neighbour.h:480 [inline] neigh_event_send include/net/neighbour.h:486 [inline] neigh_resolve_output+0x198/0x750 net/core/neighbour.c:1604 neigh_output include/net/neighbour.h:556 [inline] ip_finish_output2+0xca9/0x1070 net/ipv4/ip_output.c:237 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:438 iptunnel_xmit+0x616/0xca0 net/ipv4/ip_tunnel_core.c:97 ip_tunnel_xmit+0x193a/0x1f20 net/ipv4/ip_tunnel.c:845 __gre_xmit+0x19e/0x240 net/ipv4/ip_gre.c:490 erspan_xmit+0xa81/0x1670 net/ipv4/ip_gre.c:749 __netdev_start_xmit include/linux/netdevice.h:5325 [inline] netdev_start_xmit include/linux/netdevice.h:5334 [inline] xmit_one net/core/dev.c:3883 [inline] dev_hard_start_xmit+0x2d8/0x870 net/core/dev.c:3899 sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:347 __dev_xmit_skb net/core/dev.c:4198 [inline] __dev_queue_xmit+0x1550/0x3890 net/core/dev.c:4814 dev_queue_xmit include/linux/netdevice.h:3385 [inline] alb_send_lp_vid+0x348/0x550 drivers/net/bonding/bond_alb.c:949 alb_send_learning_packets+0x12c/0x300 drivers/net/bonding/bond_alb.c:1012 alb_fasten_mac_swap+0x639/0xf60 drivers/net/bonding/bond_alb.c:1076 bond_alb_handle_active_change+0xc6d/0xf30 drivers/net/bonding/bond_alb.c:1774 bond_change_active_slave+0x106e/0x35f0 drivers/net/bonding/bond_main.c:1307 bond_select_active_slave+0x909/0xd40 drivers/net/bonding/bond_main.c:1377 bond_enslave+0x22a5/0x3c40 drivers/net/bonding/bond_main.c:2288 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2985 rtnl_newlink_create+0x6af/0xb70 net/core/rtnetlink.c:3876 __rtnl_newlink net/core/rtnetlink.c:3979 [inline] rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4094 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6980 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg+0x183/0x260 net/socket.c:2678 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x20d/0x640 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf705ef6c Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8 RSP: 002b:00000000f544d50c EFLAGS: 00000206 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000800000c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 bond3: (slave erspan1): Enslaving as an active interface with an up link ---------------- Code disassembly (best guess): 0: 90 nop 1: 85 d2 test %edx,%edx 3: 74 0a je 0xf 5: 89 ce mov %ecx,%esi 7: 81 e6 ff 0f 00 00 and $0xfff,%esi d: 89 32 mov %esi,(%rdx) f: 85 c0 test %eax,%eax 11: 74 05 je 0x18 13: c1 e9 0c shr $0xc,%ecx 16: 89 08 mov %ecx,(%rax) 18: 31 c0 xor %eax,%eax 1a: 5e pop %rsi 1b: 5d pop %rbp 1c: c3 ret 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 58 pop %rax 3f: b8 .byte 0xb8