======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc7-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.2503/13148 is trying to acquire lock:
ffff88803fffece0 (&pgdat->kswapd_wait){..-.}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline]
ffff88803fffece0 (&pgdat->kswapd_wait){..-.}-{2:2}, at: __wake_up+0x1c/0x60 kernel/sched/wait.c:127

but task is already holding lock:
ffff8880606021f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc7/0xdb0 kernel/bpf/lpm_trie.c:333

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&trie->lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       trie_delete_elem+0xb0/0x820 kernel/bpf/lpm_trie.c:462
       0xffffffffa0001fea
       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_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449
       __traceiter_sched_switch+0x6c/0xc0 include/trace/events/sched.h:222
       trace_sched_switch include/trace/events/sched.h:222 [inline]
       __schedule+0x17cf/0x5490 kernel/sched/core.c:6526
       __schedule_loop kernel/sched/core.c:6606 [inline]
       schedule+0xe7/0x350 kernel/sched/core.c:6621
       futex_wait_queue+0xfc/0x1f0 kernel/futex/waitwake.c:370
       __futex_wait+0x291/0x3c0 kernel/futex/waitwake.c:669
       futex_wait+0xe9/0x380 kernel/futex/waitwake.c:697
       do_futex+0x22b/0x350 kernel/futex/syscalls.c:102
       __do_sys_futex_time32 kernel/futex/syscalls.c:509 [inline]
       __se_sys_futex_time32 kernel/futex/syscalls.c:492 [inline]
       __ia32_sys_futex_time32+0x1da/0x460 kernel/futex/syscalls.c:492
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #2 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:560
       raw_spin_rq_lock kernel/sched/sched.h:1415 [inline]
       rq_lock kernel/sched/sched.h:1714 [inline]
       task_fork_fair+0x73/0x250 kernel/sched/fair.c:12710
       sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4633
       copy_process+0x4710/0x6f50 kernel/fork.c:2483
       kernel_clone+0xfd/0x960 kernel/fork.c:2781
       user_mode_thread+0xb4/0xf0 kernel/fork.c:2859
       rest_init+0x23/0x2b0 init/main.c:712
       start_kernel+0x3df/0x4c0 init/main.c:1103
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x148

-> #1 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
       try_to_wake_up+0x9a/0x13e0 kernel/sched/core.c:4051
       autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:384
       __wake_up_common+0x131/0x1e0 kernel/sched/wait.c:89
       __wake_up_common_lock kernel/sched/wait.c:106 [inline]
       __wake_up+0x31/0x60 kernel/sched/wait.c:127
       wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7263
       rmqueue mm/page_alloc.c:3057 [inline]
       get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3443
       __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4702
       __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
       alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
       alloc_slab_page+0x4e/0xf0 mm/slub.c:2325
       allocate_slab mm/slub.c:2488 [inline]
       new_slab+0x84/0x260 mm/slub.c:2541
       ___slab_alloc+0xdac/0x1870 mm/slub.c:3727
       __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817
       __slab_alloc_node mm/slub.c:3870 [inline]
       slab_alloc_node mm/slub.c:4029 [inline]
       kmem_cache_alloc_noprof+0x2ae/0x2f0 mm/slub.c:4048
       radix_tree_node_alloc.constprop.0+0x1e8/0x350 lib/radix-tree.c:253
       idr_get_free+0x528/0xa40 lib/radix-tree.c:1506
       idr_alloc_u32+0x191/0x2f0 lib/idr.c:46
       idr_alloc_cyclic+0x10c/0x230 lib/idr.c:125
       __kernfs_new_node+0x11b/0x890 fs/kernfs/dir.c:630
       kernfs_new_node+0x186/0x240 fs/kernfs/dir.c:700
       kernfs_create_dir_ns+0x4c/0x150 fs/kernfs/dir.c:1061
       internal_create_group+0x34b/0xe50 fs/sysfs/group.c:167
       kernel_add_sysfs_param kernel/params.c:819 [inline]
       param_sysfs_builtin kernel/params.c:856 [inline]
       param_sysfs_builtin_init+0x28e/0x3c0 kernel/params.c:990
       do_one_initcall+0x128/0x630 init/main.c:1267
       do_initcall_level init/main.c:1329 [inline]
       do_initcalls init/main.c:1345 [inline]
       do_basic_setup init/main.c:1364 [inline]
       kernel_init_freeable+0x660/0xc50 init/main.c:1578
       kernel_init+0x1c/0x2b0 init/main.c:1467
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (&pgdat->kswapd_wait){..-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3133 [inline]
       check_prevs_add kernel/locking/lockdep.c:3252 [inline]
       validate_chain kernel/locking/lockdep.c:3868 [inline]
       __lock_acquire+0x24ed/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
       __wake_up_common_lock kernel/sched/wait.c:105 [inline]
       __wake_up+0x1c/0x60 kernel/sched/wait.c:127
       wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7263
       rmqueue mm/page_alloc.c:3057 [inline]
       get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3443
       __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4702
       __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
       alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
       alloc_slab_page+0x4e/0xf0 mm/slub.c:2325
       allocate_slab mm/slub.c:2488 [inline]
       new_slab+0x84/0x260 mm/slub.c:2541
       ___slab_alloc+0xdac/0x1870 mm/slub.c:3727
       __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817
       __slab_alloc_node mm/slub.c:3870 [inline]
       slab_alloc_node mm/slub.c:4029 [inline]
       __do_kmalloc_node mm/slub.c:4161 [inline]
       __kmalloc_node_noprof+0x367/0x440 mm/slub.c:4168
       kmalloc_node_noprof include/linux/slab.h:708 [inline]
       bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422
       lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline]
       trie_update_elem+0x1ef/0xdb0 kernel/bpf/lpm_trie.c:342
       bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203
       generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1889
       bpf_map_do_batch+0x615/0x6e0 kernel/bpf/syscall.c:5218
       __sys_bpf+0x151b/0x55e0 kernel/bpf/syscall.c:5774
       __do_sys_bpf kernel/bpf/syscall.c:5817 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5815 [inline]
       __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5815
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

other info that might help us debug this:

Chain exists of:
  &pgdat->kswapd_wait --> &rq->__lock --> &trie->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&trie->lock);
                               lock(&rq->__lock);
                               lock(&trie->lock);
  lock(&pgdat->kswapd_wait);

 *** DEADLOCK ***

2 locks held by syz.0.2503/13148:
 #0: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x24b/0x6c0 kernel/bpf/syscall.c:202
 #1: ffff8880606021f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc7/0xdb0 kernel/bpf/lpm_trie.c:333

stack backtrace:
CPU: 3 UID: 0 PID: 13148 Comm: syz.0.2503 Not tainted 6.11.0-rc7-syzkaller #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:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186
 check_prev_add kernel/locking/lockdep.c:3133 [inline]
 check_prevs_add kernel/locking/lockdep.c:3252 [inline]
 validate_chain kernel/locking/lockdep.c:3868 [inline]
 __lock_acquire+0x24ed/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
 __wake_up_common_lock kernel/sched/wait.c:105 [inline]
 __wake_up+0x1c/0x60 kernel/sched/wait.c:127
 wakeup_kswapd+0x45e/0x640 mm/vmscan.c:7263
 rmqueue mm/page_alloc.c:3057 [inline]
 get_page_from_freelist+0x9bb/0x2e50 mm/page_alloc.c:3443
 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4702
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2325
 allocate_slab mm/slub.c:2488 [inline]
 new_slab+0x84/0x260 mm/slub.c:2541
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817
 __slab_alloc_node mm/slub.c:3870 [inline]
 slab_alloc_node mm/slub.c:4029 [inline]
 __do_kmalloc_node mm/slub.c:4161 [inline]
 __kmalloc_node_noprof+0x367/0x440 mm/slub.c:4168
 kmalloc_node_noprof include/linux/slab.h:708 [inline]
 bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422
 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline]
 trie_update_elem+0x1ef/0xdb0 kernel/bpf/lpm_trie.c:342
 bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203
 generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1889
 bpf_map_do_batch+0x615/0x6e0 kernel/bpf/syscall.c:5218
 __sys_bpf+0x151b/0x55e0 kernel/bpf/syscall.c:5774
 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5815 [inline]
 __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5815
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf73ae579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f56a656c EFLAGS: 00000296 ORIG_RAX: 0000000000000165
RAX: ffffffffffffffda RBX: 000000000000001a RCX: 0000000020000000
RDX: 0000000000000038 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi