============================================ WARNING: possible recursive locking detected 5.15.110-syzkaller #0 Not tainted -------------------------------------------- sed/10883 is trying to acquire lock: ffff888147800218 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline] ffff888147800218 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4429 [inline] ffff888147800218 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 but task is already holding lock: ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline] ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4429 [inline] ffff888141789098 (_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 8 locks held by sed/10883: #0: ffffc90000dd0be0 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline] #0: ffffc90000dd0be0 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x560 kernel/time/timer.c:1411 #1: ffffffff8c91c540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:269 #2: ffffffff8c91c540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:269 #3: ffff8880243f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:373 [inline] #3: ffff8880243f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:173 [inline] #3: ffff8880243f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3806 [inline] #3: ffff8880243f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x11f2/0x3230 net/core/dev.c:4188 #4: ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline] #4: ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4429 [inline] #4: ffff888141789098 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 #5: ffffffff8c91c540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:269 #6: ffffffff8c91c540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:269 #7: ffff88801b1ab258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:373 [inline] #7: ffff88801b1ab258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:173 [inline] #7: ffff88801b1ab258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3806 [inline] #7: ffff88801b1ab258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x11f2/0x3230 net/core/dev.c:4188 stack backtrace: CPU: 1 PID: 10883 Comm: sed Not tainted 5.15.110-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 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:2946 [inline] check_deadlock kernel/locking/lockdep.c:2989 [inline] validate_chain+0x46cf/0x58b0 kernel/locking/lockdep.c:3774 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] __netif_tx_lock include/linux/netdevice.h:4429 [inline] sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340 __dev_xmit_skb net/core/dev.c:3819 [inline] __dev_queue_xmit+0x18ee/0x3230 net/core/dev.c:4188 neigh_output include/net/neighbour.h:516 [inline] ip_finish_output2+0xdbe/0x1270 net/ipv4/ip_output.c:228 iptunnel_xmit+0x50c/0x960 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x1c55/0x24a0 net/ipv4/ip_tunnel.c:810 __gre_xmit net/ipv4/ip_gre.c:469 [inline] erspan_xmit+0xa9c/0x1530 net/ipv4/ip_gre.c:715 __netdev_start_xmit include/linux/netdevice.h:5019 [inline] netdev_start_xmit include/linux/netdevice.h:5033 [inline] xmit_one net/core/dev.c:3592 [inline] dev_hard_start_xmit+0x298/0x7a0 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+0x18ee/0x3230 net/core/dev.c:4188 neigh_output include/net/neighbour.h:516 [inline] ip_finish_output2+0xdbe/0x1270 net/ipv4/ip_output.c:228 igmpv3_send_cr net/ipv4/igmp.c:720 [inline] igmp_ifc_timer_expire+0xaa3/0xf60 net/ipv4/igmp.c:810 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1737 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750 __do_softirq+0x3b3/0x93a kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 02 b8 a5 f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 e7 92 33 f7 65 8b 05 f8 ee de 75 85 c0 74 3f 48 c7 04 24 0e 36 RSP: 0018:ffffc900052cfcc0 EFLAGS: 00000206 RAX: 110dd6943c429900 RBX: 1ffff92000a59f9c RCX: ffffffff913be003 RDX: dffffc0000000000 RSI: ffffffff8a8afb60 RDI: 0000000000000001 RBP: ffffc900052cfd50 R08: ffffffff81864ef0 R09: fffffbfff22afbc0 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff92000a59f98 R14: ffffc900052cfce0 R15: 0000000000000246 debug_rcu_head_queue kernel/rcu/rcu.h:177 [inline] __call_rcu kernel/rcu/tree.c:2977 [inline] call_rcu+0xb1/0xa70 kernel/rcu/tree.c:3073 task_work_run+0x129/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:175 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f33b155ea46 Code: 10 00 00 00 44 8b 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 0c f7 d8 89 05 0a 48 01 00 48 83 c8 ff c3 31 RSP: 002b:00007ffcd8563a08 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: fffffffffffffffe RBX: 00007ffcd8563c68 RCX: 00007f33b155ea46 RDX: 0000000000080000 RSI: 00007ffcd8563a80 RDI: 00000000ffffff9c RBP: 00007ffcd8563a70 R08: 0000000000080000 R09: 00007ffcd8563a80 R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffcd8563a80 R13: 0000000000000009 R14: 00007ffcd8563c4f R15: 00000000ffffffff ---------------- Code disassembly (best guess): 0: 9c pushfq 1: 8f 44 24 20 popq 0x20(%rsp) 5: 42 80 3c 23 00 cmpb $0x0,(%rbx,%r12,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 02 b8 a5 f7 callq 0xf7a5b816 14: f6 44 24 21 02 testb $0x2,0x21(%rsp) 19: 75 4e jne 0x69 1b: 41 f7 c7 00 02 00 00 test $0x200,%r15d 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 e7 92 33 f7 callq 0xf7339316 <-- trapping instruction 2f: 65 8b 05 f8 ee de 75 mov %gs:0x75deeef8(%rip),%eax # 0x75deef2e 36: 85 c0 test %eax,%eax 38: 74 3f je 0x79 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss