syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.143-syzkaller #0 Not tainted
------------------------------------------------------
syz.1.3181/13051 is trying to acquire lock:
ffff88813fffacd8 (&zone->lock){-.-.}-{2:2}, at: rmqueue_buddy mm/page_alloc.c:3724 [inline]
ffff88813fffacd8 (&zone->lock){-.-.}-{2:2}, at: rmqueue mm/page_alloc.c:3877 [inline]
ffff88813fffacd8 (&zone->lock){-.-.}-{2:2}, at: get_page_from_freelist+0x912/0x1ac0 mm/page_alloc.c:4325

but task is already holding lock:
ffff888059291238 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc4/0xe90 kernel/bpf/lpm_trie.c:335

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&trie->lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:467
       0xffffffffa0002586
       bpf_dispatcher_nop_func include/linux/bpf.h:1001 [inline]
       __bpf_prog_run include/linux/filter.h:596 [inline]
       bpf_prog_run include/linux/filter.h:610 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline]
       bpf_trace_run2+0x30a/0x3b0 kernel/trace/bpf_trace.c:2324
       trace_contention_end+0x13f/0x190 include/trace/events/lock.h:122
       __pv_queued_spin_lock_slowpath+0x7e8/0x9c0 kernel/locking/qspinlock.c:560
       pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
       queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
       queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
       do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
       _raw_spin_lock_irqsave+0xb0/0xf0 kernel/locking/spinlock.c:162
       rmqueue_bulk mm/page_alloc.c:3131 [inline]
       __rmqueue_pcplist+0x1bf/0xfb0 mm/page_alloc.c:3785
       rmqueue_pcplist mm/page_alloc.c:3827 [inline]
       rmqueue mm/page_alloc.c:3870 [inline]
       get_page_from_freelist+0x7cd/0x1ac0 mm/page_alloc.c:4325
       __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
       alloc_slab_page+0x5d/0x160 mm/slub.c:1794
       allocate_slab mm/slub.c:1939 [inline]
       new_slab+0x87/0x2c0 mm/slub.c:1992
       ___slab_alloc+0xbc6/0x1220 mm/slub.c:3180
       __slab_alloc mm/slub.c:3279 [inline]
       slab_alloc_node mm/slub.c:3364 [inline]
       __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3437
       __do_kmalloc_node mm/slab_common.c:935 [inline]
       __kmalloc+0xa0/0x240 mm/slab_common.c:949
       kmalloc include/linux/slab.h:568 [inline]
       tomoyo_realpath_from_path+0xdf/0x5d0 security/tomoyo/realpath.c:251
       tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
       tomoyo_check_open_permission+0x1aa/0x380 security/tomoyo/file.c:771
       security_file_open+0x5e/0xa0 security/security.c:1681
       do_dentry_open+0x305/0x10d0 fs/open.c:869
       do_open fs/namei.c:3626 [inline]
       path_openat+0x25c6/0x2e70 fs/namei.c:3783
       do_filp_open+0x1c1/0x3c0 fs/namei.c:3810
       do_sys_openat2+0x142/0x490 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __x64_sys_openat+0x135/0x160 fs/open.c:1345
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&zone->lock){-.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       rmqueue_buddy mm/page_alloc.c:3724 [inline]
       rmqueue mm/page_alloc.c:3877 [inline]
       get_page_from_freelist+0x912/0x1ac0 mm/page_alloc.c:4325
       __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
       __alloc_pages_node include/linux/gfp.h:237 [inline]
       alloc_pages_node include/linux/gfp.h:260 [inline]
       __kmalloc_large_node+0x8c/0x1e0 mm/slab_common.c:1077
       __do_kmalloc_node mm/slab_common.c:924 [inline]
       __kmalloc_node+0x10e/0x240 mm/slab_common.c:943
       kmalloc_node include/linux/slab.h:589 [inline]
       bpf_map_kmalloc_node+0xb8/0x1a0 kernel/bpf/syscall.c:452
       lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline]
       trie_update_elem+0x160/0xe90 kernel/bpf/lpm_trie.c:338
       bpf_map_update_value+0x5a0/0x670 kernel/bpf/syscall.c:226
       generic_map_update_batch+0x569/0x850 kernel/bpf/syscall.c:1702
       bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1
       __sys_bpf+0x65f/0x6d0 kernel/bpf/syscall.c:-1
       __do_sys_bpf kernel/bpf/syscall.c:5124 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5122 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&trie->lock);
                               lock(&zone->lock);
                               lock(&trie->lock);
  lock(&zone->lock);

 *** DEADLOCK ***

2 locks held by syz.1.3181/13051:
 #0: ffffffff8cb2aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2aaa0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x379/0x670 kernel/bpf/syscall.c:225
 #1: ffff888059291238 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc4/0xe90 kernel/bpf/lpm_trie.c:335

stack backtrace:
CPU: 1 PID: 13051 Comm: syz.1.3181 Not tainted 6.1.143-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 rmqueue_buddy mm/page_alloc.c:3724 [inline]
 rmqueue mm/page_alloc.c:3877 [inline]
 get_page_from_freelist+0x912/0x1ac0 mm/page_alloc.c:4325
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_pages_node include/linux/gfp.h:260 [inline]
 __kmalloc_large_node+0x8c/0x1e0 mm/slab_common.c:1077
 __do_kmalloc_node mm/slab_common.c:924 [inline]
 __kmalloc_node+0x10e/0x240 mm/slab_common.c:943
 kmalloc_node include/linux/slab.h:589 [inline]
 bpf_map_kmalloc_node+0xb8/0x1a0 kernel/bpf/syscall.c:452
 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline]
 trie_update_elem+0x160/0xe90 kernel/bpf/lpm_trie.c:338
 bpf_map_update_value+0x5a0/0x670 kernel/bpf/syscall.c:226
 generic_map_update_batch+0x569/0x850 kernel/bpf/syscall.c:1702
 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1
 __sys_bpf+0x65f/0x6d0 kernel/bpf/syscall.c:-1
 __do_sys_bpf kernel/bpf/syscall.c:5124 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5122 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdddd18e929
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:00007fddddfe2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fdddd3b6080 RCX: 00007fdddd18e929
RDX: 0000000000000038 RSI: 0000200000000680 RDI: 000000000000001a
RBP: 00007fdddd210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdddd3b6080 R15: 00007fffe1c60008
 </TASK>