====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.1368/10551 is trying to acquire lock: ffff88806060b238 (&trie->lock){-...}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 but task is already holding lock: ffff8880b8e37d68 (stock_lock){-.-.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b8e37d68 (stock_lock){-.-.}-{2:2}, at: refill_stock+0xed/0x450 mm/memcontrol.c:2355 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_obj_stock mm/memcontrol.c:3267 [inline] obj_cgroup_charge+0x10a/0x630 mm/memcontrol.c:3397 memcg_slab_pre_alloc_hook mm/slab.h:508 [inline] slab_pre_alloc_hook+0x2e7/0x310 mm/slab.h:719 slab_alloc_node mm/slub.c:3477 [inline] __kmem_cache_alloc_node+0x53/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node+0xa4/0x230 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+0x169/0xea0 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x660/0x720 kernel/bpf/syscall.c:203 generic_map_update_batch+0x5ec/0x810 kernel/bpf/syscall.c:1800 bpf_map_do_batch+0x3d7/0x610 kernel/bpf/syscall.c:5010 __sys_bpf+0x381/0x890 kernel/bpf/syscall.c:-1 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline] __se_sys_bpf kernel/bpf/syscall.c:5579 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 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+0x2df1/0x7d40 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+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:605 [inline] bpf_prog_run include/linux/filter.h:623 [inline] bpf_prog_run_array include/linux/bpf.h:1994 [inline] trace_call_bpf+0x3ad/0x6c0 kernel/trace/bpf_trace.c:143 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10295 perf_trace_lock_acquire+0x34f/0x410 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] percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline] percpu_ref_put+0x35/0x180 include/linux/percpu-refcount.h:351 css_put include/linux/cgroup_refcnt.h:79 [inline] drain_stock mm/memcontrol.c:2304 [inline] __refill_stock+0x134/0x3f0 mm/memcontrol.c:2341 refill_stock+0x19c/0x450 mm/memcontrol.c:2356 try_charge_memcg+0x12ac/0x1800 mm/memcontrol.c:2807 try_charge mm/memcontrol.c:2865 [inline] charge_memcg+0x11b/0x3a0 mm/memcontrol.c:7090 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:7111 mem_cgroup_charge include/linux/memcontrol.h:686 [inline] shmem_add_to_page_cache+0x904/0x1b30 mm/shmem.c:784 shmem_get_folio_gfp+0xf08/0x2aa0 mm/shmem.c:2071 shmem_get_folio mm/shmem.c:2164 [inline] shmem_write_begin+0xf2/0x420 mm/shmem.c:2706 generic_perform_write+0x2fe/0x5c0 mm/filemap.c:4036 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:2883 __kernel_write_iter+0x28c/0x690 fs/read_write.c:517 dump_emit_page fs/coredump.c:957 [inline] dump_user_range+0x420/0x860 fs/coredump.c:984 elf_core_dump+0x31d0/0x3770 fs/binfmt_elf.c:2184 do_coredump+0x17cc/0x24d0 fs/coredump.c:833 get_signal+0x1133/0x13f0 kernel/signal.c:2888 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315 exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 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.2.1368/10551: #0: ffff88801bbe8418 (sb_writers#5){.+.+}-{0:0}, at: do_coredump+0x17ab/0x24d0 fs/coredump.c:832 #1: ffff888078ec53a8 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff888078ec53a8 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:2873 #2: ffff8880b8e37d68 (stock_lock){-.-.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #2: ffff8880b8e37d68 (stock_lock){-.-.}-{2:2}, at: refill_stock+0xed/0x450 mm/memcontrol.c:2355 #3: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xc3/0x6c0 kernel/trace/bpf_trace.c:142 stack backtrace: CPU: 0 PID: 10551 Comm: syz.2.1368 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0x2df1/0x7d40 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+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:605 [inline] bpf_prog_run include/linux/filter.h:623 [inline] bpf_prog_run_array include/linux/bpf.h:1994 [inline] trace_call_bpf+0x3ad/0x6c0 kernel/trace/bpf_trace.c:143 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10295 perf_trace_lock_acquire+0x34f/0x410 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] percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline] percpu_ref_put+0x35/0x180 include/linux/percpu-refcount.h:351 css_put include/linux/cgroup_refcnt.h:79 [inline] drain_stock mm/memcontrol.c:2304 [inline] __refill_stock+0x134/0x3f0 mm/memcontrol.c:2341 refill_stock+0x19c/0x450 mm/memcontrol.c:2356 try_charge_memcg+0x12ac/0x1800 mm/memcontrol.c:2807 try_charge mm/memcontrol.c:2865 [inline] charge_memcg+0x11b/0x3a0 mm/memcontrol.c:7090 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:7111 mem_cgroup_charge include/linux/memcontrol.h:686 [inline] shmem_add_to_page_cache+0x904/0x1b30 mm/shmem.c:784 shmem_get_folio_gfp+0xf08/0x2aa0 mm/shmem.c:2071 shmem_get_folio mm/shmem.c:2164 [inline] shmem_write_begin+0xf2/0x420 mm/shmem.c:2706 generic_perform_write+0x2fe/0x5c0 mm/filemap.c:4036 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:2883 __kernel_write_iter+0x28c/0x690 fs/read_write.c:517 dump_emit_page fs/coredump.c:957 [inline] dump_user_range+0x420/0x860 fs/coredump.c:984 elf_core_dump+0x31d0/0x3770 fs/binfmt_elf.c:2184 do_coredump+0x17cc/0x24d0 fs/coredump.c:833 get_signal+0x1133/0x13f0 kernel/signal.c:2888 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315 exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fe441a52877 Code: e8 8e fa ff ff 89 f2 48 8d 3d 0d 40 1b 00 48 8d 35 c4 fa 1d 00 31 c0 e8 e7 f8 ff ff 0f 1f 80 00 00 00 00 53 89 fb 48 83 ec 10 <64> 8b 04 25 a4 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8 RSP: 002b:00007fe442a28120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fe441b9cdd9 RDX: 00007fe442a28140 RSI: 00007fe442a28270 RDI: 000000000000000b RBP: 00007fe441c32d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000400 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fe441e16128 R14: 00007fe441e16090 R15: 00007fff31b821c8