====================================================== WARNING: possible circular locking dependency detected 6.6.96-syzkaller #0 Not tainted ------------------------------------------------------ syz.0.417/7872 is trying to acquire lock: ffff888074e64238 (&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+0x1f8/0x360 mm/memcontrol.c:3298 refill_obj_stock+0x1e7/0x680 mm/memcontrol.c:3341 memcg_slab_free_hook+0x125/0x1f0 mm/slab.h:576 slab_free mm/slub.c:3811 [inline] kmem_cache_free+0xe1/0x280 mm/slub.c:3838 rcu_do_batch kernel/rcu/tree.c:2194 [inline] rcu_core+0xcc4/0x1720 kernel/rcu/tree.c:2467 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 kasan_check_range+0x6/0x290 mm/kasan/generic.c:186 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:504 [inline] cpu_online include/linux/cpumask.h:1082 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xbc/0x410 kernel/locking/lockdep.c:5725 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] dput+0x57/0x1e0 fs/dcache.c:904 path_put+0x39/0x60 fs/namei.c:562 do_readlinkat+0x3ef/0x480 fs/stat.c:509 __do_sys_readlink fs/stat.c:527 [inline] __se_sys_readlink fs/stat.c:524 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:524 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+0x67c/0x740 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_2c29ac5cdc6b1842+0x42/0x46 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] __count_memcg_events+0x194/0x320 mm/memcontrol.c:915 mem_cgroup_charge_statistics mm/memcontrol.c:943 [inline] charge_memcg+0x1be/0x380 mm/memcontrol.c:7056 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:7069 mem_cgroup_charge include/linux/memcontrol.h:686 [inline] shmem_add_to_page_cache+0x8e7/0x1b40 mm/shmem.c:785 shmem_get_folio_gfp+0xf05/0x2ac0 mm/shmem.c:2072 shmem_fault+0x1b6/0x7f0 mm/shmem.c:2249 __do_fault+0x13b/0x4e0 mm/memory.c:4243 do_read_fault mm/memory.c:4616 [inline] do_fault mm/memory.c:4753 [inline] do_pte_missing mm/memory.c:3688 [inline] handle_pte_fault mm/memory.c:5025 [inline] __handle_mm_fault mm/memory.c:5166 [inline] handle_mm_fault+0x3886/0x4920 mm/memory.c:5331 faultin_page mm/gup.c:868 [inline] __get_user_pages+0x5ea/0x1470 mm/gup.c:1167 populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593 __mm_populate+0x24c/0x380 mm/gup.c:1696 mm_populate include/linux/mm.h:3312 [inline] vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561 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 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 *** 3 locks held by syz.0.417/7872: #0: ffff888077f3c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:146 [inline] #0: ffff888077f3c420 (&mm->mmap_lock){++++}-{3:3}, at: __mm_populate+0x16f/0x380 mm/gup.c:1675 #1: ffff8880b8f2c468 (per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)){-.-.}-{2:2}, at: cgroup_rstat_updated+0xf7/0x360 kernel/cgroup/rstat.c:45 #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361 stack backtrace: CPU: 1 PID: 7872 Comm: syz.0.417 Not tainted 6.6.96-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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_2c29ac5cdc6b1842+0x42/0x46 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] __count_memcg_events+0x194/0x320 mm/memcontrol.c:915 mem_cgroup_charge_statistics mm/memcontrol.c:943 [inline] charge_memcg+0x1be/0x380 mm/memcontrol.c:7056 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:7069 mem_cgroup_charge include/linux/memcontrol.h:686 [inline] shmem_add_to_page_cache+0x8e7/0x1b40 mm/shmem.c:785 shmem_get_folio_gfp+0xf05/0x2ac0 mm/shmem.c:2072 shmem_fault+0x1b6/0x7f0 mm/shmem.c:2249 __do_fault+0x13b/0x4e0 mm/memory.c:4243 do_read_fault mm/memory.c:4616 [inline] do_fault mm/memory.c:4753 [inline] do_pte_missing mm/memory.c:3688 [inline] handle_pte_fault mm/memory.c:5025 [inline] __handle_mm_fault mm/memory.c:5166 [inline] handle_mm_fault+0x3886/0x4920 mm/memory.c:5331 faultin_page mm/gup.c:868 [inline] __get_user_pages+0x5ea/0x1470 mm/gup.c:1167 populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593 __mm_populate+0x24c/0x380 mm/gup.c:1696 mm_populate include/linux/mm.h:3312 [inline] vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561 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 RIP: 0033:0x7fb7ac38e929 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:00007fb7ad24a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fb7ac5b5fa0 RCX: 00007fb7ac38e929 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fb7ac410b39 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb7ac5b5fa0 R15: 00007fff735e09a8