============================================ WARNING: possible recursive locking detected 6.14.0-rc2-syzkaller-00039-g09fbf3d50205 #0 Not tainted -------------------------------------------- syz.0.526/7498 is trying to acquire lock: ffff8880327f11e0 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x2b6/0x360 kernel/bpf/queue_stack_maps.c:105 but task is already holding lock: ffff888051fd89e0 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x353/0x420 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 syz.0.526/7498: #0: ffffffff8e320ea8 (pcpu_alloc_mutex){+.+.}-{4:4}, at: pcpu_alloc_noprof+0xc5a/0x1680 mm/percpu.c:1782 #1: ffffffff8e320f18 (pcpu_lock){..-.}-{3:3}, at: pcpu_alloc_noprof+0x2ab/0x1680 mm/percpu.c:1788 #2: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #2: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: __queue_work+0xf2/0x1080 kernel/workqueue.c:2259 #3: ffff88806a93db58 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x6c9/0x1080 kernel/workqueue.c:2296 #4: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #4: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #4: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run1+0x1ba/0x580 kernel/trace/bpf_trace.c:2411 #5: ffff888051fd89e0 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x353/0x420 kernel/bpf/queue_stack_maps.c:210 #6: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #6: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #6: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #6: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2412 stack backtrace: CPU: 3 UID: 0 PID: 7498 Comm: syz.0.526 Not tainted 6.14.0-rc2-syzkaller-00039-g09fbf3d50205 #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: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 __queue_map_get+0x2b6/0x360 kernel/bpf/queue_stack_maps.c:105 bpf_prog_00798911c748094f+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:692 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x34c/0x590 kernel/trace/bpf_trace.c:2412 __bpf_trace_contention_end+0xca/0x110 include/trace/events/lock.h:122 __traceiter_contention_end+0x5a/0xa0 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end.constprop.0+0xf0/0x170 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: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 queue_stack_map_push_elem+0x353/0x420 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x40/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:692 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run1+0x344/0x580 kernel/trace/bpf_trace.c:2411 __bpf_trace_workqueue_activate_work+0x98/0xd0 include/trace/events/workqueue.h:59 __do_trace_workqueue_activate_work include/trace/events/workqueue.h:59 [inline] trace_workqueue_activate_work+0x131/0x1f0 include/trace/events/workqueue.h:59 __queue_work+0x96d/0x1080 kernel/workqueue.c:2338 queue_work_on+0x11a/0x140 kernel/workqueue.c:2390 queue_work include/linux/workqueue.h:662 [inline] schedule_work include/linux/workqueue.h:723 [inline] pcpu_schedule_balance_work mm/percpu.c:204 [inline] pcpu_schedule_balance_work mm/percpu.c:201 [inline] pcpu_alloc_noprof+0xc42/0x1680 mm/percpu.c:1856 bpf_map_alloc_percpu+0x9a/0x4b0 kernel/bpf/syscall.c:555 bpf_array_alloc_percpu kernel/bpf/arraymap.c:38 [inline] array_map_alloc+0x52d/0x730 kernel/bpf/arraymap.c:152 map_create+0x5c5/0x1d20 kernel/bpf/syscall.c:1446 __sys_bpf+0x4391/0x49c0 kernel/bpf/syscall.c:5776 __do_sys_bpf kernel/bpf/syscall.c:5901 [inline] __se_sys_bpf kernel/bpf/syscall.c:5899 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5899 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f789158cde9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f78924b6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f78917a5fa0 RCX: 00007f789158cde9 RDX: 0000000000000048 RSI: 0000400000000b00 RDI: 2000000000000000 RBP: 00007f789160e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f78917a5fa0 R15: 00007ffe5c438478