============================================ WARNING: possible recursive locking detected 6.9.0-syzkaller-05151-g1b294a1f3561 #0 Not tainted -------------------------------------------- syz-executor.3/13201 is trying to acquire lock: ffff88805ee9f1d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 but task is already holding lock: ffff88805ee9f1d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x14b/0x4d0 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 syz-executor.3/13201: #0: ffff8880229fe5d8 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #0: ffff8880229fe5d8 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x258/0x1740 kernel/signal.c:2699 #1: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #1: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x24c/0x5a0 kernel/trace/bpf_trace.c:2445 #2: ffff88805ee9f1d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105 #3: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8e3361e0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444 stack backtrace: CPU: 0 PID: 13201 Comm: syz-executor.3 Not tainted 6.9.0-syzkaller-05151-g1b294a1f3561 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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+0x15c1/0x58e0 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 queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x3f/0x43 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+0x2ec/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_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105 bpf_prog_94b194d4ebfffdd5+0x45/0x49 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+0x33a/0x5a0 kernel/trace/bpf_trace.c:2445 __traceiter_kmem_cache_free+0x33/0x50 include/trace/events/kmem.h:114 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x267/0x2d0 mm/slub.c:4416 __sigqueue_free kernel/signal.c:451 [inline] collect_signal kernel/signal.c:594 [inline] __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:616 dequeue_signal+0x169/0x5a0 kernel/signal.c:639 get_signal+0x602/0x1740 kernel/signal.c:2790 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f25c147cee9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff8d54d608 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 0000000000057b57 RCX: 00007f25c147cee9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f25c15abf8c RBP: 00007fff8d54d710 R08: 7fffffffffffffff R09: 000000000000007e R10: 00007fff8d54d6f0 R11: 0000000000000246 R12: 0000000000057b89 R13: 00007f25c15abf8c R14: 00007fff8d54d6f0 R15: 0000000000000032