netlink: 'syz.4.401': attribute type 1 has an invalid length. bond3: entered promiscuous mode 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 Not tainted -------------------------------------------- syz.4.401/7614 is trying to acquire lock: ffff88807a390958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline] ffff88807a390958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4847 [inline] ffff88807a390958 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370 but task is already holding lock: ffff88807ebc0158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline] ffff88807ebc0158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4847 [inline] ffff88807ebc0158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 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 locks held by syz.4.401/7614: 10, last CPU#0: #0: ffffffff907bb0e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff907bb0e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff907bb0e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595 #1: ffffffff902524e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff902524e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #1: ffffffff902524e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc1d/0x1c30 net/core/rtnetlink.c:4241 #2: ffffffff8ed5c900 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #2: ffffffff8ed5c900 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:902 [inline] #2: ffffffff8ed5c900 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x29b/0x3820 net/core/dev.c:4844 #3: ffff8880669d9228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:359 [inline] #3: ffff8880669d9228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:206 [inline] #3: ffff8880669d9228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4249 [inline] #3: ffff8880669d9228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x1143/0x3820 net/core/dev.c:4884 #4: ffff88807ebc0158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline] #4: ffff88807ebc0158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4847 [inline] #4: ffff88807ebc0158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370 #5: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #5: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #5: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5a/0x450 net/ipv4/ip_output.c:432 #6: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #6: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #6: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x3de/0x10b0 net/ipv4/ip_output.c:229 #7: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #7: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #7: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x23/0x270 net/ipv4/arp.c:666 #8: ffffffff8ed5c900 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8ed5c900 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:902 [inline] #8: ffffffff8ed5c900 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x29b/0x3820 net/core/dev.c:4844 #9: ffff88807a7cc228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:359 [inline] #9: ffff88807a7cc228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:206 [inline] #9: ffff88807a7cc228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4249 [inline] #9: ffff88807a7cc228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x1143/0x3820 net/core/dev.c:4884 stack backtrace: CPU: 0 UID: 0 PID: 7614 Comm: syz.4.401 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/08/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x27a/0x290 kernel/locking/lockdep.c:3085 check_deadlock kernel/locking/lockdep.c:3137 [inline] validate_chain kernel/locking/lockdep.c:3939 [inline] __lock_acquire+0x25db/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __raw_spin_lock include/linux/spinlock_api_smp.h:190 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:173 spin_lock include/linux/spinlock.h:347 [inline] __netif_tx_lock include/linux/netdevice.h:4847 [inline] sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370 __dev_xmit_skb net/core/dev.c:4262 [inline] __dev_queue_xmit+0x177f/0x3820 net/core/dev.c:4884 NF_HOOK+0x33a/0x3c0 include/linux/netfilter.h:-1 arp_xmit+0x16c/0x270 net/ipv4/arp.c:668 arp_solicit+0xbdc/0xe40 net/ipv4/arp.c:395 neigh_probe net/core/neighbour.c:1087 [inline] __neigh_event_send+0xf0c/0x1510 net/core/neighbour.c:1267 neigh_event_send_probe include/net/neighbour.h:474 [inline] neigh_event_send include/net/neighbour.h:480 [inline] neigh_resolve_output+0x1a1/0x720 net/core/neighbour.c:1604 neigh_output include/net/neighbour.h:554 [inline] ip_finish_output2+0xc4b/0x10b0 net/ipv4/ip_output.c:236 NF_HOOK_COND include/linux/netfilter.h:314 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:437 iptunnel_xmit+0x626/0xd10 net/ipv4/ip_tunnel_core.c:97 ip_tunnel_xmit+0x195b/0x2040 net/ipv4/ip_tunnel.c:846 erspan_xmit+0xb6a/0x1620 net/ipv4/ip_gre.c:752 __netdev_start_xmit include/linux/netdevice.h:5438 [inline] netdev_start_xmit include/linux/netdevice.h:5447 [inline] xmit_one net/core/dev.c:3937 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3953 sch_direct_xmit+0x257/0x4c0 net/sched/sch_generic.c:372 __dev_xmit_skb net/core/dev.c:4262 [inline] __dev_queue_xmit+0x177f/0x3820 net/core/dev.c:4884 dev_queue_xmit include/linux/netdevice.h:3466 [inline] alb_send_lp_vid+0x348/0x550 drivers/net/bonding/bond_alb.c:968 alb_send_learning_packets+0x12c/0x300 drivers/net/bonding/bond_alb.c:1031 alb_fasten_mac_swap+0x45d/0xf70 drivers/net/bonding/bond_alb.c:1095 bond_alb_handle_active_change+0xbc5/0xe50 drivers/net/bonding/bond_alb.c:1825 bond_change_active_slave+0x1098/0x36d0 drivers/net/bonding/bond_main.c:1309 bond_select_active_slave+0x8a6/0xcd0 drivers/net/bonding/bond_main.c:1379 bond_enslave+0x239c/0x3b10 drivers/net/bonding/bond_main.c:2298 do_set_master+0x563/0x720 net/core/rtnetlink.c:3089 rtnl_newlink_create+0x4c8/0x7b0 net/core/rtnetlink.c:4009 __rtnl_newlink net/core/rtnetlink.c:4125 [inline] rtnl_newlink+0x167a/0x1c30 net/core/rtnetlink.c:4242 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7159 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2713 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767 __sys_sendmsg net/socket.c:2799 [inline] __do_sys_sendmsg net/socket.c:2804 [inline] __se_sys_sendmsg net/socket.c:2802 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19cdb9e159 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:00007f19cbdf6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f19cde25fa0 RCX: 00007f19cdb9e159 RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007f19cdc3503b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f19cde26038 R14: 00007f19cde25fa0 R15: 00007ffe0b5f5ed8 bond3: (slave erspan1): Enslaving as an active interface with an up link syz.4.401 (7614) used obsolete PPPIOCDETACH ioctl syz.4.401 (7614) used greatest stack depth: 16968 bytes left