============================================ WARNING: possible recursive locking detected 6.14.0-rc7-syzkaller-00074-ga7f2e10ecd8f #0 Not tainted -------------------------------------------- kworker/u8:5/64 is trying to acquire lock: ffffc900048190d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x36e/0x4b0 kernel/bpf/ringbuf.c:423 but task is already holding lock: ffffc900031f00d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x36e/0x4b0 kernel/bpf/ringbuf.c:423 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&rb->spinlock); lock(&rb->spinlock); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by kworker/u8:5/64: #0: ffff88801beee148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90001557d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fee46d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xca/0xb30 net/core/net_namespace.c:606 #3: ffffffff8fefa3e8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x8c/0xae0 net/core/dev.c:12420 #4: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #4: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #4: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2412 #5: ffffc900031f00d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x36e/0x4b0 kernel/bpf/ringbuf.c:423 #6: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #6: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #6: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #6: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2412 stack backtrace: CPU: 1 UID: 0 PID: 64 Comm: kworker/u8:5 Not tainted 6.14.0-rc7-syzkaller-00074-ga7f2e10ecd8f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_deadlock_bug+0x2e3/0x410 kernel/locking/lockdep.c:3039 check_deadlock kernel/locking/lockdep.c:3091 [inline] validate_chain kernel/locking/lockdep.c:3893 [inline] __lock_acquire+0x2117/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x36e/0x4b0 kernel/bpf/ringbuf.c:423 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:474 [inline] bpf_ringbuf_reserve+0x57/0x90 kernel/bpf/ringbuf.c:466 bpf_prog_fe0ed97373b08409+0x2e/0x4f bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x234/0x590 kernel/trace/bpf_trace.c:2412 __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline] class_preempt_notrace_destructor include/linux/preempt.h:481 [inline] __do_trace_contention_begin include/trace/events/lock.h:95 [inline] trace_contention_begin.constprop.0+0xf3/0x170 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x10b/0xc90 kernel/locking/qspinlock.c:402 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:577 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x210/0x2c0 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x36e/0x4b0 kernel/bpf/ringbuf.c:423 ____bpf_ringbuf_output kernel/bpf/ringbuf.c:549 [inline] bpf_ringbuf_output+0x62/0xd0 kernel/bpf/ringbuf.c:539 bpf_prog_918f90024333f9ff+0x43/0x4b bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x234/0x590 kernel/trace/bpf_trace.c:2412 __do_trace_kfree include/trace/events/kmem.h:94 [inline] trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x244/0x4d0 mm/slub.c:4744 neigh_sysctl_unregister+0x67/0x80 net/core/neighbour.c:3821 addrconf_ifdown.isra.0+0x1520/0x1af0 net/ipv6/addrconf.c:4005 addrconf_notify+0x220/0x19c0 net/ipv6/addrconf.c:3775 notifier_call_chain+0xba/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2206 call_netdevice_notifiers_extack net/core/dev.c:2244 [inline] call_netdevice_notifiers net/core/dev.c:2258 [inline] unregister_netdevice_many_notify+0xc8a/0x1f30 net/core/dev.c:11887 unregister_netdevice_many net/core/dev.c:11951 [inline] default_device_exit_batch+0x867/0xae0 net/core/dev.c:12434 ops_exit_list+0x12b/0x180 net/core/net_namespace.c:177 cleanup_net+0x5c6/0xb30 net/core/net_namespace.c:652 process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3400 kthread+0x3b2/0x750 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state