============================================ WARNING: possible recursive locking detected 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0 Not tainted -------------------------------------------- ksoftirqd/3/34 is trying to acquire lock: ffff88804c4a21d8 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x2a8/0x350 kernel/bpf/queue_stack_maps.c:140 but task is already holding lock: ffff888054d4d1d8 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x2a8/0x350 kernel/bpf/queue_stack_maps.c:140 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 ksoftirqd/3/34: #0: ffffffff8ddb9ec0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8ddb9ec0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2563 [inline] #0: ffffffff8ddb9ec0 (rcu_callback){....}-{0:0}, at: rcu_core+0x7cc/0x16b0 kernel/rcu/tree.c:2843 #1: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #1: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #1: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x1d1/0x5a0 kernel/trace/bpf_trace.c:2448 #2: ffff888054d4d1d8 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x2a8/0x350 kernel/bpf/queue_stack_maps.c:140 #3: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #3: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2447 stack backtrace: CPU: 3 UID: 0 PID: 34 Comm: ksoftirqd/3 Not tainted 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain kernel/locking/lockdep.c:3855 [inline] __lock_acquire+0x2167/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __stack_map_get+0x2a8/0x350 kernel/bpf/queue_stack_maps.c:140 bpf_prog_00798911c748094f+0x42/0x46 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:2406 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 trace_contention_end.constprop.0+0xea/0x170 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x27e/0xc90 kernel/locking/qspinlock.c:557 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 __stack_map_get+0x2a8/0x350 kernel/bpf/queue_stack_maps.c:140 bpf_prog_00798911c748094f+0x42/0x46 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:2406 [inline] bpf_trace_run3+0x240/0x5a0 kernel/trace/bpf_trace.c:2448 __traceiter_kmem_cache_free+0x35/0x50 include/trace/events/kmem.h:114 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x1dd/0x3a0 mm/slub.c:4551 rcu_do_batch kernel/rcu/tree.c:2569 [inline] rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2843 handle_softirqs+0x216/0x8f0 kernel/softirq.c:554 run_ksoftirqd kernel/softirq.c:928 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:920 smpboot_thread_fn+0x661/0xa10 kernel/smpboot.c:164 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