============================================ WARNING: possible recursive locking detected 6.9.0-syzkaller-08410-gff2632d7d08e #0 Not tainted -------------------------------------------- kworker/u32:7/1093 is trying to acquire lock: ffff888046c7e1d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x2b8/0x360 kernel/bpf/queue_stack_maps.c:105 but task is already holding lock: ffff8880475dc1d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x2b8/0x360 kernel/bpf/queue_stack_maps.c:105 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 4 locks held by kworker/u32:7/1093: #0: ffff8880154b0018 (&pool->lock){-.-.}-{2:2}, at: process_one_work+0xc09/0x1b60 kernel/workqueue.c:3266 #1: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #1: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2444 #2: ffff8880475dc1d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x2b8/0x360 kernel/bpf/queue_stack_maps.c:105 #3: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8dbb1ce0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 2 PID: 1093 Comm: kworker/u32:7 Not tainted 6.9.0-syzkaller-08410-gff2632d7d08e #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Workqueue: events_unbound flush_to_ldisc Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x20e6/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __queue_map_get+0x2b8/0x360 kernel/bpf/queue_stack_maps.c:105 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 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+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 __traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95 trace_contention_begin.constprop.0+0xed/0x170 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x112/0xcc0 kernel/locking/qspinlock.c:402 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [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 __queue_map_get+0x2b8/0x360 kernel/bpf/queue_stack_maps.c:105 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2012 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2253 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+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95 __traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95 trace_contention_begin.constprop.0+0xed/0x170 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x112/0xcc0 kernel/locking/qspinlock.c:402 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [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 process_one_work+0xc09/0x1b60 kernel/workqueue.c:3266 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244