============================================ WARNING: possible recursive locking detected 6.10.0-rc5-syzkaller #0 Not tainted -------------------------------------------- kworker/1:6/5183 is trying to acquire lock: ffff888078dc51d8 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140 but task is already holding lock: ffff888078dc51d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&qs->lock); lock(&qs->lock); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by kworker/1:6/5183: #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90003907d00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90003907d00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff88802e018250 (&devlink->lock_key#7){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x57/0xaa0 drivers/net/netdevsim/dev.c:838 #3: ffff88801cfb80e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff88801cfb80e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:791 [inline] #3: ffff88801cfb80e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: nsim_dev_trap_report_work+0x195/0xaa0 drivers/net/netdevsim/dev.c:850 #4: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #4: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x24c/0x5a0 kernel/trace/bpf_trace.c:2445 #5: ffff888078dc51d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 #6: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #6: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #6: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #6: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 1 PID: 5183 Comm: kworker/1:6 Not tainted 6.10.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: events nsim_dev_trap_report_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140 bpf_prog_94b194d4ebfffdd5+0x45/0x4d bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x2ee/0x540 kernel/trace/bpf_trace.c:2444 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb81/0xdc0 kernel/locking/qspinlock.c:557 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline] queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x272/0x370 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x3f/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run3+0x33c/0x5a0 kernel/trace/bpf_trace.c:2445 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x2a9/0x350 mm/slub.c:4511 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x765/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244