====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.15741/18012 is trying to acquire lock: ffff8880668ba238 (&trie->lock){-.-.}-{2:2} , at: trie_delete_elem+0x94/0x630 kernel/bpf/lpm_trie.c:466 but task is already holding lock: ffff8880b8e37de8 ( stock_lock){-.-.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] stock_lock){-.-.}-{2:2}, at: refill_obj_stock+0xef/0x6a0 mm/memcontrol.c:3366 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (stock_lock){-.-.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] consume_stock mm/memcontrol.c:2274 [inline] try_charge_memcg+0x237/0x17c0 mm/memcontrol.c:2684 obj_cgroup_charge_pages mm/memcontrol.c:3138 [inline] __memcg_kmem_charge_page+0x224/0x380 mm/memcontrol.c:3164 __alloc_pages+0x222/0x460 mm/page_alloc.c:4518 __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_pages_node include/linux/gfp.h:260 [inline] __kmalloc_large_node+0x8c/0x1f0 mm/slab_common.c:1148 __do_kmalloc_node mm/slab_common.c:995 [inline] __kmalloc_node+0x112/0x240 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] bpf_map_kmalloc_node+0xbc/0x1b0 kernel/bpf/syscall.c:424 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x172/0xd60 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x64b/0x710 kernel/bpf/syscall.c:203 map_update_elem+0x586/0x710 kernel/bpf/syscall.c:1567 __sys_bpf+0x6b5/0x890 kernel/bpf/syscall.c:5466 __do_sys_bpf kernel/bpf/syscall.c:5582 [inline] __se_sys_bpf kernel/bpf/syscall.c:5580 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5580 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 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+0x37ef/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x94/0x630 kernel/bpf/lpm_trie.c:466 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:617 [inline] bpf_prog_run include/linux/filter.h:624 [inline] bpf_prog_run_array include/linux/bpf.h:1994 [inline] trace_call_bpf+0x333/0x6c0 kernel/trace/bpf_trace.c:143 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10287 perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] mod_objcg_mlstate+0xad/0x320 mm/memcontrol.c:2913 drain_obj_stock+0x154/0x3a0 mm/memcontrol.c:3321 refill_obj_stock+0x1fc/0x6a0 mm/memcontrol.c:3370 memcg_slab_free_hook+0x123/0x200 mm/slab.h:576 slab_free mm/slub.c:3825 [inline] __kmem_cache_free+0xa3/0x1f0 mm/slub.c:3843 security_cred_free+0xc0/0xf0 security/security.c:3066 put_cred_rcu+0x68/0x2a0 kernel/cred.c:78 rcu_do_batch kernel/rcu/tree.c:2194 [inline] rcu_core+0x9c1/0x17f0 kernel/rcu/tree.c:2467 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 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 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 find_get_context+0x53e/0x660 kernel/events/core.c:-1 __do_sys_perf_event_open kernel/events/core.c:12758 [inline] __se_sys_perf_event_open+0xaa7/0x1c60 kernel/events/core.c:12601 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(stock_lock); lock(&trie->lock); lock(stock_lock); lock(&trie->lock); *** DEADLOCK *** 4 locks held by syz.3.15741/18012: #0: ffff88802833d6e0 (&sig->exec_update_lock){++++}-{3:3}, at: __do_sys_perf_event_open kernel/events/core.c:12740 [inline] #0: ffff88802833d6e0 (&sig->exec_update_lock){++++}-{3:3}, at: __se_sys_perf_event_open+0x96c/0x1c60 kernel/events/core.c:12601 #1: ffffffff8d131ec0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8d131ec0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2188 [inline] #1: ffffffff8d131ec0 (rcu_callback){....}-{0:0}, at: rcu_core+0x951/0x17f0 kernel/rcu/tree.c:2467 #2: ffff8880b8e37de8 (stock_lock){-.-.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #2: ffff8880b8e37de8 (stock_lock){-.-.}-{2:2}, at: refill_obj_stock+0xef/0x6a0 mm/memcontrol.c:3366 #3: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xc3/0x6c0 kernel/trace/bpf_trace.c:142 stack backtrace: CPU: 0 PID: 18012 Comm: syz.3.15741 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 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+0x37ef/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x94/0x630 kernel/bpf/lpm_trie.c:466 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:617 [inline] bpf_prog_run include/linux/filter.h:624 [inline] bpf_prog_run_array include/linux/bpf.h:1994 [inline] trace_call_bpf+0x333/0x6c0 kernel/trace/bpf_trace.c:143 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10287 perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] mod_objcg_mlstate+0xad/0x320 mm/memcontrol.c:2913 drain_obj_stock+0x154/0x3a0 mm/memcontrol.c:3321 refill_obj_stock+0x1fc/0x6a0 mm/memcontrol.c:3370 memcg_slab_free_hook+0x123/0x200 mm/slab.h:576 slab_free mm/slub.c:3825 [inline] __kmem_cache_free+0xa3/0x1f0 mm/slub.c:3843 security_cred_free+0xc0/0xf0 security/security.c:3066 put_cred_rcu+0x68/0x2a0 kernel/cred.c:78 rcu_do_batch kernel/rcu/tree.c:2194 [inline] rcu_core+0x9c1/0x17f0 kernel/rcu/tree.c:2467 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 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 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 fb 4e c6 f6 65 8b 05 5c 1d 6d 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90004407c40 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: 1a2afb2967f32200 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001 RBP: ffffc90004407cd8 R08: ffffffff911eb5a7 R09: 1ffffffff223d6b4 R10: dffffc0000000000 R11: fffffbfff223d6b5 R12: dffffc0000000000 R13: 1ffff110051c1785 R14: ffff8880780e0000 R15: 1ffff92000880f88 find_get_context+0x53e/0x660 kernel/events/core.c:-1 __do_sys_perf_event_open kernel/events/core.c:12758 [inline] __se_sys_perf_event_open+0xaa7/0x1c60 kernel/events/core.c:12601 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe9bab9e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe9bbae7028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fe9bae25fa0 RCX: 00007fe9bab9e0d9 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000200000000040 RBP: 00007fe9bac35024 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe9bae26038 R14: 00007fe9bae25fa0 R15: 00007ffcbed89248 ---------------- Code disassembly (best guess): 0: c7 44 24 20 00 00 00 movl $0x0,0x20(%rsp) 7: 00 8: 9c pushf 9: 8f 44 24 20 pop 0x20(%rsp) d: f7 44 24 20 00 02 00 testl $0x200,0x20(%rsp) 14: 00 15: 41 c6 04 07 f8 movb $0xf8,(%r15,%rax,1) 1a: 75 4b jne 0x67 1c: f7 c3 00 02 00 00 test $0x200,%ebx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 fb 4e c6 f6 call 0xf6c64f2a <-- trapping instruction 2f: 65 8b 05 5c 1d 6d 75 mov %gs:0x756d1d5c(%rip),%eax # 0x756d1d92 36: 85 c0 test %eax,%eax 38: 74 3c je 0x76 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss