erspan1: entered allmulticast mode bond4: (slave erspan1): making interface the new active one erspan1: entered promiscuous mode ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.4.8247/15014 is trying to acquire lock: ffff8880562c8558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] ffff8880562c8558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4713 [inline] ffff8880562c8558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 but task is already holding lock: ffff8880567b4158 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] ffff8880567b4158 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4713 [inline] ffff8880567b4158 (&qdisc_xmit_lock_key#3){+.-.}-{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#3); lock(&qdisc_xmit_lock_key#3); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by syz.4.8247/15014: #0: ffffffff90123948 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff90123948 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff90123948 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbbe808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 #2: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #2: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #2: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4754 #3: ffff88803181a228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:353 [inline] #3: ffff88803181a228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #3: ffff88803181a228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4166 [inline] #3: ffff88803181a228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x1002/0x3850 net/core/dev.c:4795 #4: ffff8880567b4158 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] #4: ffff8880567b4158 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4713 [inline] #4: ffff8880567b4158 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 #5: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #5: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #5: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450 net/ipv4/ip_output.c:433 #6: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #6: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #6: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x3c2/0x1070 net/ipv4/ip_output.c:230 #7: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #7: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #7: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x23/0x270 net/ipv4/arp.c:663 #8: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #8: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4754 #9: ffff888029ec2228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:353 [inline] #9: ffff888029ec2228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #9: ffff888029ec2228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4166 [inline] #9: ffff888029ec2228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x1002/0x3850 net/core/dev.c:4795 stack backtrace: CPU: 0 UID: 0 PID: 15014 Comm: syz.4.8247 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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+0x106/0x330 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:4713 [inline] sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:4179 [inline] __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4795 NF_HOOK+0x33a/0x3c0 include/linux/netfilter.h:-1 arp_xmit+0x16c/0x270 net/ipv4/arp.c:665 arp_solicit+0xbe0/0xe40 net/ipv4/arp.c:392 neigh_probe net/core/neighbour.c:1096 [inline] __neigh_event_send+0xf05/0x14a0 net/core/neighbour.c:1276 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:1603 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+0x59f/0xa00 net/ipv4/ip_tunnel_core.c:84 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:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3880 sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:347 __dev_xmit_skb net/core/dev.c:4179 [inline] __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4795 dev_queue_xmit include/linux/netdevice.h:3384 [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:1302 bond_select_active_slave+0x909/0xd40 drivers/net/bonding/bond_main.c:1372 bond_enslave+0x22a5/0x3c40 drivers/net/bonding/bond_main.c:2237 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963 rtnl_newlink_create+0x6af/0xb70 net/core/rtnetlink.c:3854 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x1666/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 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+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa27b59c629 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:00007fa27c3a0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa27b816090 RCX: 00007fa27b59c629 RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fa27b632b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa27b816128 R14: 00007fa27b816090 R15: 00007fffd705a158 bond4: (slave erspan1): Enslaving as an active interface with an up link syz.4.8247 (15014) used greatest stack depth: 16584 bytes left