============================================ WARNING: possible recursive locking detected 6.1.81-syzkaller #0 Not tainted -------------------------------------------- syz-executor.0/12154 is trying to acquire lock: ffff88807caaa458 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88807caaa458 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline] ffff88807caaa458 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 but task is already holding lock: ffff88807ca024d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88807ca024d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline] ffff88807ca024d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 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 syz-executor.0/12154: #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:319 [inline] #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:760 [inline] #0: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x402/0x1310 net/ipv4/ip_output.c:221 #1: ffffffff8d12a8a0 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #1: ffffffff8d12a8a0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:812 [inline] #1: ffffffff8d12a8a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2d6/0x3cf0 net/core/dev.c:4216 #2: ffff88803b722258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline] #2: ffff88803b722258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline] #2: ffff88803b722258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3841 [inline] #2: ffff88803b722258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x131b/0x3cf0 net/core/dev.c:4259 #3: ffff88807ca024d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff88807ca024d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline] #3: ffff88807ca024d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 #4: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:319 [inline] #4: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:760 [inline] #4: ffffffff8d12a840 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x402/0x1310 net/ipv4/ip_output.c:221 #5: ffffffff8d12a8a0 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #5: ffffffff8d12a8a0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:812 [inline] #5: ffffffff8d12a8a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2d6/0x3cf0 net/core/dev.c:4216 #6: ffff888020bad258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline] #6: ffff888020bad258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline] #6: ffff888020bad258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3841 [inline] #6: ffff888020bad258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x131b/0x3cf0 net/core/dev.c:4259 stack backtrace: CPU: 0 PID: 12154 Comm: syz-executor.0 Not tainted 6.1.81-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2983 [inline] check_deadlock kernel/locking/lockdep.c:3026 [inline] validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __netif_tx_lock include/linux/netdevice.h:4304 [inline] sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 __dev_xmit_skb net/core/dev.c:3854 [inline] __dev_queue_xmit+0x1ace/0x3cf0 net/core/dev.c:4259 neigh_output include/net/neighbour.h:544 [inline] ip_finish_output2+0xe35/0x1310 net/ipv4/ip_output.c:228 iptunnel_xmit+0x513/0x920 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x22e4/0x2cc0 net/ipv4/ip_tunnel.c:827 __gre_xmit net/ipv4/ip_gre.c:469 [inline] erspan_xmit+0xaa2/0x1530 net/ipv4/ip_gre.c:718 __netdev_start_xmit include/linux/netdevice.h:4853 [inline] netdev_start_xmit include/linux/netdevice.h:4867 [inline] xmit_one net/core/dev.c:3627 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643 sch_direct_xmit+0x2b2/0x5e0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3854 [inline] __dev_queue_xmit+0x1ace/0x3cf0 net/core/dev.c:4259 neigh_output include/net/neighbour.h:544 [inline] ip_finish_output2+0xe35/0x1310 net/ipv4/ip_output.c:228 dst_output include/net/dst.h:444 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x113/0x1a0 net/ipv4/ip_output.c:1596 udp_send_skb+0xa33/0x1420 net/ipv4/udp.c:981 udp_sendmsg+0x1d10/0x2ad0 net/ipv4/udp.c:1268 udpv6_sendmsg+0xd1e/0x30f0 net/ipv6/udp.c:1407 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514 ___sys_sendmsg net/socket.c:2568 [inline] __sys_sendmmsg+0x3ab/0x730 net/socket.c:2654 __do_sys_sendmmsg net/socket.c:2683 [inline] __se_sys_sendmmsg net/socket.c:2680 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2680 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe5f587dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe5f66200c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007fe5f59abf80 RCX: 00007fe5f587dda9 RDX: 0000000000006c00 RSI: 0000000020007e40 RDI: 0000000000000007 RBP: 00007fe5f58ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fe5f59abf80 R15: 00007ffccfb7b198 netlink: 'syz-executor.0': attribute type 27 has an invalid length. bridge0: port 2(bridge_slave_1) entered disabled state bridge0: port 1(bridge_slave_0) entered disabled state batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 device macsec0 left promiscuous mode netdevsim netdevsim0 netdevsim0: unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim1: unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim2: unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim3: unset [1, 0] type 2 family 0 port 6081 - 0 device wireguard0 left promiscuous mode device wireguard1 left promiscuous mode device wireguard2 left promiscuous mode