====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.2609/13456 is trying to acquire lock: ffff88805e22f238 (&trie->lock){..-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 but task is already holding lock: ffff8880b8f2c468 (per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)){-.-.}-{2:2}, at: cgroup_rstat_updated+0xf7/0x360 kernel/cgroup/rstat.c:45 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 cgroup_rstat_updated+0xf7/0x360 kernel/cgroup/rstat.c:45 memcg_rstat_updated mm/memcontrol.c:626 [inline] __mod_memcg_lruvec_state+0x1d8/0x360 mm/memcontrol.c:827 mod_memcg_lruvec_state include/linux/memcontrol.h:1065 [inline] mod_objcg_mlstate+0x1c9/0x310 mm/memcontrol.c:2887 drain_obj_stock+0x164/0x360 mm/memcontrol.c:3292 refill_obj_stock+0x1e7/0x680 mm/memcontrol.c:3341 obj_cgroup_charge+0x3c3/0x620 mm/memcontrol.c:3402 memcg_slab_pre_alloc_hook mm/slab.h:508 [inline] slab_pre_alloc_hook+0x2eb/0x310 mm/slab.h:719 slab_alloc_node mm/slub.c:3467 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x5a/0x2e0 mm/slub.c:3509 vm_area_dup+0x27/0x270 kernel/fork.c:501 __split_vma+0x19f/0xc00 mm/mmap.c:2373 mprotect_fixup+0xa0f/0xc90 mm/mprotect.c:644 do_mprotect_pkey+0x76e/0xc30 mm/mprotect.c:819 __do_sys_mprotect mm/mprotect.c:840 [inline] __se_sys_mprotect mm/mprotect.c:837 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:837 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (stock_lock){..-.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] consume_stock mm/memcontrol.c:2245 [inline] try_charge_memcg+0x213/0x1810 mm/memcontrol.c:2655 obj_cgroup_charge_pages mm/memcontrol.c:3109 [inline] __memcg_kmem_charge_page+0x224/0x380 mm/memcontrol.c:3135 __alloc_pages+0x219/0x460 mm/page_alloc.c:4474 __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:1148 __do_kmalloc_node mm/slab_common.c:995 [inline] __kmalloc_node+0x10f/0x230 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] bpf_map_kmalloc_node+0xbc/0x1b0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x166/0xea0 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x660/0x720 kernel/bpf/syscall.c:201 map_update_elem+0x57b/0x700 kernel/bpf/syscall.c:1561 __sys_bpf+0x652/0x800 kernel/bpf/syscall.c:5455 __do_sys_bpf kernel/bpf/syscall.c:5571 [inline] __se_sys_bpf kernel/bpf/syscall.c:5569 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5569 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&trie->lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 bpf_prog_ae0c3e605f35524c+0x45/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361 __bpf_trace_contention_end+0xdd/0x130 include/trace/events/lock.h:122 trace_contention_end+0xe6/0x110 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x7ec/0x9d0 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [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+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xb4/0xf0 kernel/locking/spinlock.c:162 cgroup_rstat_updated+0xf7/0x360 kernel/cgroup/rstat.c:45 memcg_rstat_updated mm/memcontrol.c:626 [inline] __mod_memcg_lruvec_state+0x1d8/0x360 mm/memcontrol.c:827 __mod_lruvec_state mm/memcontrol.c:849 [inline] __mod_lruvec_page_state+0x1f3/0x420 mm/memcontrol.c:870 __lruvec_stat_mod_folio include/linux/vmstat.h:615 [inline] page_remove_rmap+0x519/0xc30 mm/rmap.c:1446 zap_pte_range mm/memory.c:1453 [inline] zap_pmd_range mm/memory.c:1570 [inline] zap_pud_range mm/memory.c:1599 [inline] zap_p4d_range mm/memory.c:1620 [inline] unmap_page_range+0x151f/0x2fe0 mm/memory.c:1641 unmap_vmas+0x25e/0x3a0 mm/memory.c:1731 exit_mmap+0x200/0xb50 mm/mmap.c:3302 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &trie->lock --> stock_lock --> per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu) Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)); lock(stock_lock); lock(per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)); lock(&trie->lock); *** DEADLOCK *** 6 locks held by syz.1.2609/13456: #0: ffff88801c65f3a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:146 [inline] #0: ffff88801c65f3a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x14a/0xb50 mm/mmap.c:3287 #1: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #1: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x2c/0x2c0 mm/pgtable-generic.c:287 #2: ffff88802c9341f8 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88802c9341f8 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0x107/0x1e0 mm/pgtable-generic.c:375 #3: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: __mod_lruvec_page_state+0xa5/0x420 mm/memcontrol.c:860 #4: ffff8880b8f2c468 (per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)){-.-.}-{2:2}, at: cgroup_rstat_updated+0xf7/0x360 kernel/cgroup/rstat.c:45 #5: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #5: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #5: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #5: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361 stack backtrace: CPU: 1 PID: 13456 Comm: syz.1.2609 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 bpf_prog_ae0c3e605f35524c+0x45/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361 __bpf_trace_contention_end+0xdd/0x130 include/trace/events/lock.h:122 trace_contention_end+0xe6/0x110 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x7ec/0x9d0 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [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+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xb4/0xf0 kernel/locking/spinlock.c:162 cgroup_rstat_updated+0xf7/0x360 kernel/cgroup/rstat.c:45 memcg_rstat_updated mm/memcontrol.c:626 [inline] __mod_memcg_lruvec_state+0x1d8/0x360 mm/memcontrol.c:827 __mod_lruvec_state mm/memcontrol.c:849 [inline] __mod_lruvec_page_state+0x1f3/0x420 mm/memcontrol.c:870 __lruvec_stat_mod_folio include/linux/vmstat.h:615 [inline] page_remove_rmap+0x519/0xc30 mm/rmap.c:1446 zap_pte_range mm/memory.c:1453 [inline] zap_pmd_range mm/memory.c:1570 [inline] zap_pud_range mm/memory.c:1599 [inline] zap_p4d_range mm/memory.c:1620 [inline] unmap_page_range+0x151f/0x2fe0 mm/memory.c:1641 unmap_vmas+0x25e/0x3a0 mm/memory.c:1731 exit_mmap+0x200/0xb50 mm/mmap.c:3302 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa022f8ebe9 Code: Unable to access opcode bytes at 0x7fa022f8ebbf. RSP: 002b:00007fa023dd9038 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffea RBX: 00007fa0231c6090 RCX: 00007fa022f8ebe9 RDX: 0000000000001f00 RSI: 0000200000000500 RDI: 0000000000000009 RBP: 00007fa023011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa0231c6128 R14: 00007fa0231c6090 R15: 00007ffdb15522a8