============================================ WARNING: possible recursive locking detected 5.3.0+ #0 Not tainted -------------------------------------------- ksoftirqd/1/16 is trying to acquire lock: ffff8880a21c26d8 (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] ffff8880a21c26d8 (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3903 [inline] ffff8880a21c26d8 (_xmit_ETHER#2){+.-.}, at: sch_direct_xmit+0x2e0/0xc30 net/sched/sch_generic.c:311 but task is already holding lock: ffff88809436e0d8 (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] ffff88809436e0d8 (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3903 [inline] ffff88809436e0d8 (_xmit_ETHER#2){+.-.}, at: sch_direct_xmit+0x2e0/0xc30 net/sched/sch_generic.c:311 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(_xmit_ETHER#2); lock(_xmit_ETHER#2); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by ksoftirqd/1/16: #0: ffff8880a67165f8 (dev->qdisc_running_key ?: &qdisc_running_key){+...}, at: __do_softirq+0x262/0x98c kernel/softirq.c:292 #1: ffff88809436e0d8 (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] #1: ffff88809436e0d8 (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3903 [inline] #1: ffff88809436e0d8 (_xmit_ETHER#2){+.-.}, at: sch_direct_xmit+0x2e0/0xc30 net/sched/sch_generic.c:311 #2: ffff888219ef66e0 (k-slock-AF_INET){+.-.}, at: spin_trylock include/linux/spinlock.h:348 [inline] #2: ffff888219ef66e0 (k-slock-AF_INET){+.-.}, at: icmp_xmit_lock net/ipv4/icmp.c:214 [inline] #2: ffff888219ef66e0 (k-slock-AF_INET){+.-.}, at: __icmp_send+0x6e1/0x1410 net/ipv4/icmp.c:667 #3: ffffffff88fab240 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #3: ffffffff88fab240 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 net/ipv4/ip_output.c:214 #4: ffffffff88fab240 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x35b0 net/core/dev.c:3808 #5: ffff888089b62890 (&(&sch->seqlock)->rlock){+...}, at: spin_trylock include/linux/spinlock.h:348 [inline] #5: ffff888089b62890 (&(&sch->seqlock)->rlock){+...}, at: qdisc_run_begin include/net/sch_generic.h:158 [inline] #5: ffff888089b62890 (&(&sch->seqlock)->rlock){+...}, at: __dev_xmit_skb net/core/dev.c:3471 [inline] #5: ffff888089b62890 (&(&sch->seqlock)->rlock){+...}, at: __dev_queue_xmit+0x24cf/0x35b0 net/core/dev.c:3842 #6: ffff888089b62778 (dev->qdisc_running_key ?: &qdisc_running_key){+...}, at: dev_queue_xmit+0x18/0x20 net/core/dev.c:3906 stack backtrace: CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_deadlock_bug kernel/locking/lockdep.c:2371 [inline] check_deadlock kernel/locking/lockdep.c:2412 [inline] validate_chain kernel/locking/lockdep.c:2955 [inline] __lock_acquire.cold+0x188/0x398 kernel/locking/lockdep.c:3955 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] __netif_tx_lock include/linux/netdevice.h:3903 [inline] sch_direct_xmit+0x2e0/0xc30 net/sched/sch_generic.c:311 __dev_xmit_skb net/core/dev.c:3481 [inline] __dev_queue_xmit+0x283d/0x35b0 net/core/dev.c:3842 dev_queue_xmit+0x18/0x20 net/core/dev.c:3906 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0x21f/0x640 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:436 [inline] ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1555 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1575 icmp_push_reply+0x350/0x4a0 net/ipv4/icmp.c:389 __icmp_send+0xc44/0x1410 net/ipv4/icmp.c:738 icmp_send include/net/icmp.h:43 [inline] tnl_update_pmtu+0x4a8/0x12d0 net/ipv4/ip_tunnel.c:515 ip_tunnel_xmit+0x83e/0x2b9b net/ipv4/ip_tunnel.c:773 __gre_xmit+0x5e9/0x9a0 net/ipv4/ip_gre.c:444 erspan_xmit+0x912/0x2890 net/ipv4/ip_gre.c:679 __netdev_start_xmit include/linux/netdevice.h:4420 [inline] netdev_start_xmit include/linux/netdevice.h:4434 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296 sch_direct_xmit+0x372/0xc30 net/sched/sch_generic.c:313 qdisc_restart net/sched/sch_generic.c:376 [inline] __qdisc_run+0x577/0x1a00 net/sched/sch_generic.c:384 qdisc_run include/net/pkt_sched.h:126 [inline] qdisc_run include/net/pkt_sched.h:118 [inline] net_tx_action+0x558/0xd10 net/core/dev.c:4632 __do_softirq+0x262/0x98c kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:603 [inline] run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595 smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1