============================================ WARNING: possible recursive locking detected 4.16.0-rc4+ #263 Not tainted -------------------------------------------- syz-executor6/6546 is trying to acquire lock: (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] spin_lock include/linux/spinlock.h:310 [inline] (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] __netif_tx_lock include/linux/netdevice.h:3571 [inline] (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] sch_direct_xmit+0x361/0x1140 net/sched/sch_generic.c:325 but task is already holding lock: (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] spin_lock include/linux/spinlock.h:310 [inline] (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] __netif_tx_lock include/linux/netdevice.h:3571 [inline] (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] sch_direct_xmit+0x361/0x1140 net/sched/sch_generic.c:325 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 11 locks held by syz-executor6/6546: #0: (rcu_read_lock_bh){....}, at: [<00000000c0058dfe>] lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #0: (rcu_read_lock_bh){....}, at: [<00000000c0058dfe>] ip_finish_output2+0x2aa/0x1550 net/ipv4/ip_output.c:213 #1: (rcu_read_lock_bh){....}, at: [<000000000adc7db2>] __dev_queue_xmit+0x2f6/0x2f30 net/core/dev.c:3483 #2: (rcu_read_lock_bh){....}, at: [<00000000c0058dfe>] lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #2: (rcu_read_lock_bh){....}, at: [<00000000c0058dfe>] ip_finish_output2+0x2aa/0x1550 net/ipv4/ip_output.c:213 #3: (rcu_read_lock_bh){....}, at: [<000000000adc7db2>] __dev_queue_xmit+0x2f6/0x2f30 net/core/dev.c:3483 #4: (rcu_read_lock){....}, at: [<00000000f6ca9cd9>] br_dev_xmit+0x11d/0x1550 net/bridge/br_device.c:43 #5: (rcu_read_lock_bh){....}, at: [<000000000adc7db2>] __dev_queue_xmit+0x2f6/0x2f30 net/core/dev.c:3483 #6: (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] spin_lock include/linux/spinlock.h:310 [inline] #6: (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] __netif_tx_lock include/linux/netdevice.h:3571 [inline] #6: (_xmit_ETHER#2){+.-.}, at: [<00000000d3642ea2>] sch_direct_xmit+0x361/0x1140 net/sched/sch_generic.c:325 #7: (rcu_read_lock_bh){....}, at: [<00000000c0058dfe>] lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #7: (rcu_read_lock_bh){....}, at: [<00000000c0058dfe>] ip_finish_output2+0x2aa/0x1550 net/ipv4/ip_output.c:213 #8: (rcu_read_lock_bh){....}, at: [<000000000adc7db2>] __dev_queue_xmit+0x2f6/0x2f30 net/core/dev.c:3483 #9: (rcu_read_lock){....}, at: [<00000000f6ca9cd9>] br_dev_xmit+0x11d/0x1550 net/bridge/br_device.c:43 #10: (rcu_read_lock_bh){....}, at: [<000000000adc7db2>] __dev_queue_xmit+0x2f6/0x2f30 net/core/dev.c:3483 stack backtrace: CPU: 1 PID: 6546 Comm: syz-executor6 Not tainted 4.16.0-rc4+ #263 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_deadlock_bug kernel/locking/lockdep.c:1761 [inline] check_deadlock kernel/locking/lockdep.c:1805 [inline] validate_chain kernel/locking/lockdep.c:2401 [inline] __lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:310 [inline] __netif_tx_lock include/linux/netdevice.h:3571 [inline] sch_direct_xmit+0x361/0x1140 net/sched/sch_generic.c:325 qdisc_restart net/sched/sch_generic.c:393 [inline] __qdisc_run+0x57d/0x19c0 net/sched/sch_generic.c:401 __dev_xmit_skb net/core/dev.c:3217 [inline] __dev_queue_xmit+0xd5e/0x2f30 net/core/dev.c:3517 dev_queue_xmit+0x17/0x20 net/core/dev.c:3582 br_dev_queue_push_xmit+0x196/0x5a0 net/bridge/br_forward.c:55 NF_HOOK include/linux/netfilter.h:288 [inline] br_forward_finish+0xc8/0x530 net/bridge/br_forward.c:67 NF_HOOK include/linux/netfilter.h:288 [inline] __br_forward+0x533/0xc80 net/bridge/br_forward.c:112 br_flood+0x665/0x770 net/bridge/br_forward.c:225 br_dev_xmit+0xfbe/0x1550 net/bridge/br_device.c:103 __netdev_start_xmit include/linux/netdevice.h:4076 [inline] netdev_start_xmit include/linux/netdevice.h:4085 [inline] xmit_one net/core/dev.c:3026 [inline] dev_hard_start_xmit+0x24e/0xac0 net/core/dev.c:3042 __dev_queue_xmit+0x2637/0x2f30 net/core/dev.c:3549 dev_queue_xmit+0x17/0x20 net/core/dev.c:3582 neigh_hh_output include/net/neighbour.h:472 [inline] neigh_output include/net/neighbour.h:480 [inline] ip_finish_output2+0xf4d/0x1550 net/ipv4/ip_output.c:229 ip_finish_output+0x864/0xd10 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:277 [inline] ip_output+0x1d2/0x860 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:444 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 iptunnel_xmit+0x556/0x810 net/ipv4/ip_tunnel_core.c:91 ip_tunnel_xmit+0x177b/0x3550 net/ipv4/ip_tunnel.c:768 __gre_xmit+0x546/0x8b0 net/ipv4/ip_gre.c:449 erspan_xmit+0x779/0x22a0 net/ipv4/ip_gre.c:731 __netdev_start_xmit include/linux/netdevice.h:4076 [inline] netdev_start_xmit include/linux/netdevice.h:4085 [inline] xmit_one net/core/dev.c:3026 [inline] dev_hard_start_xmit+0x24e/0xac0 net/core/dev.c:3042 sch_direct_xmit+0x40d/0x1140 net/sched/sch_generic.c:327 qdisc_restart net/sched/sch_generic.c:393 [inline] __qdisc_run+0x57d/0x19c0 net/sched/sch_generic.c:401 __dev_xmit_skb net/core/dev.c:3217 [inline] __dev_queue_xmit+0xd5e/0x2f30 net/core/dev.c:3517 dev_queue_xmit+0x17/0x20 net/core/dev.c:3582 br_dev_queue_push_xmit+0x196/0x5a0 net/bridge/br_forward.c:55 NF_HOOK include/linux/netfilter.h:288 [inline] br_forward_finish+0xc8/0x530 net/bridge/br_forward.c:67 NF_HOOK include/linux/netfilter.h:288 [inline] __br_forward+0x533/0xc80 net/bridge/br_forward.c:112 br_flood+0x665/0x770 net/bridge/br_forward.c:225 br_dev_xmit+0xfbe/0x1550 net/bridge/br_device.c:103 __netdev_start_xmit include/linux/netdevice.h:4076 [inline] netdev_start_xmit include/linux/netdevice.h:4085 [inline] xmit_one net/core/dev.c:3026 [inline] dev_hard_start_xmit+0x24e/0xac0 net/core/dev.c:3042 __dev_queue_xmit+0x2637/0x2f30 net/core/dev.c:3549 dev_queue_xmit+0x17/0x20 net/core/dev.c:3582 neigh_resolve_output+0x5e2/0xa00 net/core/neighbour.c:1350 neigh_output include/net/neighbour.h:482 [inline] ip_finish_output2+0x91a/0x1550 net/ipv4/ip_output.c:229 ip_finish_output+0x864/0xd10 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:277 [inline] ip_output+0x1d2/0x860 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:444 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 iptunnel_xmit+0x556/0x810 net/ipv4/ip_tunnel_core.c:91 ip_tunnel_xmit+0x177b/0x3550 net/ipv4/ip_tunnel.c:768 __gre_xmit+0x546/0x8b0 net/ipv4/ip_gre.c:449 ipgre_xmit+0x89c/0xa30 net/ipv4/ip_gre.c:689 __netdev_start_xmit include/linux/netdevice.h:4076 [inline] netdev_start_xmit include/linux/netdevice.h:4085 [inline] xmit_one net/core/dev.c:3026 [inline] dev_hard_start_xmit+0x24e/0xac0 net/core/dev.c:3042 __dev_queue_xmit+0x2637/0x2f30 net/core/dev.c:3549 dev_queue_xmit+0x17/0x20 net/core/dev.c:3582 neigh_connected_output+0x49b/0x730 net/core/neighbour.c:1379 neigh_output include/net/neighbour.h:482 [inline] ip_finish_output2+0x91a/0x1550 net/ipv4/ip_output.c:229 ip_finish_output+0x864/0xd10 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:277 [inline] ip_output+0x1d2/0x860 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:444 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1414 udp_send_skb+0x351/0xc30 net/ipv4/udp.c:809 udp_sendmsg+0xba0/0x2f70 net/ipv4/udp.c:1044 udpv6_sendmsg+0x757/0x3400 net/ipv6/udp.c:1156 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xca/0x110 net/socket.c:639 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2047 __sys_sendmsg+0xe5/0x210 net/socket.c:2081 SYSC_sendmsg net/socket.c:2092 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2088 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007fd270bd6c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd270bd76d4 RCX: 0000000000453e69 RDX: 0000000000000000 RSI: 0000000020000b40 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004b9 R14: 00000000006f71f8 R15: 0000000000000000