============================================ WARNING: possible recursive locking detected 6.1.21-syzkaller #0 Not tainted -------------------------------------------- syz-executor.3/10994 is trying to acquire lock: ffff88807c6e1458 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] ffff88807c6e1458 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4300 [inline] ffff88807c6e1458 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 but task is already holding lock: ffff888026ca58d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] ffff888026ca58d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4300 [inline] ffff888026ca58d8 (_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 9 locks held by syz-executor.3/10994: #0: ffffffff8cf266a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306 #1: ffffffff8cf26700 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306 #2: ffffffff8cf26700 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306 #3: ffffffff8cf26700 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306 #4: ffff888083121258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline] #4: ffff888083121258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #4: ffff888083121258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3806 [inline] #4: ffff888083121258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x13f1/0x3c20 net/core/dev.c:4224 #5: ffff888026ca58d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] #5: ffff888026ca58d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4300 [inline] #5: ffff888026ca58d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 #6: ffffffff8cf26700 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306 #7: ffffffff8cf26700 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306 #8: ffff88807b81c258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline] #8: ffff88807b81c258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #8: ffff88807b81c258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3806 [inline] #8: ffff88807b81c258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x13f1/0x3c20 net/core/dev.c:4224 stack backtrace: CPU: 1 PID: 10994 Comm: syz-executor.3 Not tainted 6.1.21-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 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:2991 [inline] check_deadlock kernel/locking/lockdep.c:3034 [inline] validate_chain+0x4726/0x58e0 kernel/locking/lockdep.c:3819 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 __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:350 [inline] __netif_tx_lock include/linux/netdevice.h:4300 [inline] sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 __dev_xmit_skb net/core/dev.c:3819 [inline] __dev_queue_xmit+0x1ab4/0x3c20 net/core/dev.c:4224 neigh_output include/net/neighbour.h:546 [inline] ip_finish_output2+0xdd1/0x1280 net/ipv4/ip_output.c:228 iptunnel_xmit+0x50c/0x930 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x2296/0x2c70 net/ipv4/ip_tunnel.c:813 __gre_xmit net/ipv4/ip_gre.c:469 [inline] erspan_xmit+0xaa4/0x17a0 net/ipv4/ip_gre.c:715 __netdev_start_xmit include/linux/netdevice.h:4849 [inline] netdev_start_xmit include/linux/netdevice.h:4863 [inline] xmit_one net/core/dev.c:3592 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3608 sch_direct_xmit+0x2b2/0x5e0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3819 [inline] __dev_queue_xmit+0x1ab4/0x3c20 net/core/dev.c:4224 neigh_output include/net/neighbour.h:546 [inline] ip_finish_output2+0xdd1/0x1280 net/ipv4/ip_output.c:228 iptunnel_xmit+0x50c/0x930 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x2296/0x2c70 net/ipv4/ip_tunnel.c:813 __gre_xmit net/ipv4/ip_gre.c:469 [inline] ipgre_xmit+0x759/0xa60 net/ipv4/ip_gre.c:661 __netdev_start_xmit include/linux/netdevice.h:4849 [inline] netdev_start_xmit include/linux/netdevice.h:4863 [inline] xmit_one net/core/dev.c:3592 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3608 __dev_queue_xmit+0x1b97/0x3c20 net/core/dev.c:4258 dev_queue_xmit include/linux/netdevice.h:3017 [inline] __bpf_tx_skb net/core/filter.c:2117 [inline] __bpf_redirect_no_mac net/core/filter.c:2151 [inline] __bpf_redirect+0x9f3/0x1120 net/core/filter.c:2174 ____bpf_clone_redirect net/core/filter.c:2441 [inline] bpf_clone_redirect+0x249/0x360 net/core/filter.c:2413 bpf_prog_bebbfe2050753572+0x56/0x5b bpf_dispatcher_nop_func include/linux/bpf.h:975 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] bpf_test_run+0x40f/0x8b0 net/bpf/test_run.c:402 bpf_prog_test_run_skb+0xaf1/0x13a0 net/bpf/test_run.c:1180 bpf_prog_test_run+0x32f/0x3a0 kernel/bpf/syscall.c:3628 __sys_bpf+0x3eb/0x6c0 kernel/bpf/syscall.c:4981 __do_sys_bpf kernel/bpf/syscall.c:5067 [inline] __se_sys_bpf kernel/bpf/syscall.c:5065 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5065 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fbd64c8c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbd6592d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fbd64dabf80 RCX: 00007fbd64c8c0f9 RDX: 000000000000002c RSI: 0000000020000080 RDI: 000000000000000a RBP: 00007fbd64ce7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcb9c5a77f R14: 00007fbd6592d300 R15: 0000000000022000