====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz-executor/7104 is trying to acquire lock: ffff88802807a238 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x94/0x630 kernel/bpf/lpm_trie.c:466 but task is already holding lock: ffff8880b8e37da8 (stock_lock){-.-.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b8e37da8 (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:5479 __do_sys_bpf kernel/bpf/syscall.c:5595 [inline] __se_sys_bpf kernel/bpf/syscall.c:5593 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5593 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:5756 __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_b23e3725e72cf264+0x4a/0x4e 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:10295 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:5727 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+0xe1/0x290 mm/slub.c:3852 __exit_signal kernel/exit.c:216 [inline] release_task+0x111f/0x1690 kernel/exit.c:262 wait_task_zombie kernel/exit.c:1218 [inline] wait_consider_task+0x19d9/0x2e80 kernel/exit.c:1445 do_wait_thread kernel/exit.c:1508 [inline] do_wait+0x2f9/0xab0 kernel/exit.c:1625 kernel_wait4+0x22f/0x2b0 kernel/exit.c:1788 __do_sys_wait4 kernel/exit.c:1816 [inline] __se_sys_wait4 kernel/exit.c:1812 [inline] __x64_sys_wait4+0x167/0x240 kernel/exit.c:1812 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 *** 3 locks held by syz-executor/7104: #0: ffffffff8ce0a058 (tasklist_lock){.+.+}-{2:2}, at: release_task+0x43e/0x1690 kernel/exit.c:259 #1: ffff8880b8e37da8 (stock_lock){-.-.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff8880b8e37da8 (stock_lock){-.-.}-{2:2}, at: refill_obj_stock+0xef/0x6a0 mm/memcontrol.c:3366 #2: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #2: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #2: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xc3/0x6c0 kernel/trace/bpf_trace.c:142 stack backtrace: CPU: 0 PID: 7104 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 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:5756 __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_b23e3725e72cf264+0x4a/0x4e 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:10295 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:5727 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+0xe1/0x290 mm/slub.c:3852 __exit_signal kernel/exit.c:216 [inline] release_task+0x111f/0x1690 kernel/exit.c:262 wait_task_zombie kernel/exit.c:1218 [inline] wait_consider_task+0x19d9/0x2e80 kernel/exit.c:1445 do_wait_thread kernel/exit.c:1508 [inline] do_wait+0x2f9/0xab0 kernel/exit.c:1625 kernel_wait4+0x22f/0x2b0 kernel/exit.c:1788 __do_sys_wait4 kernel/exit.c:1816 [inline] __se_sys_wait4 kernel/exit.c:1812 [inline] __x64_sys_wait4+0x167/0x240 kernel/exit.c:1812 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: 0033:0x7f9ccd35e98e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffd1efb5d48 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 000055557c5cc500 RCX: 00007f9ccd35e98e RDX: 0000000040000001 RSI: 00007ffd1efb5dec RDI: ffffffffffffffff RBP: 00007ffd1efb5dec R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000000da R13: 00000000000927c0 R14: 00000000000491d3 R15: 00007ffd1efb5e40