====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.2406/15118 is trying to acquire lock: ffff8880297ec238 (&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: mod_objcg_state+0x101/0x8c0 mm/memcontrol.c:3203 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_01ffad9a3ed37586+0x4d/0x51 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:606 [inline] bpf_prog_run include/linux/filter.h:624 [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+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 mod_objcg_state+0x2c4/0x8c0 mm/memcontrol.c:3223 memcg_slab_post_alloc_hook mm/slab.h:544 [inline] slab_post_alloc_hook+0x358/0x4d0 mm/slab.h:778 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc_lru+0x175/0x2b0 mm/slub.c:3526 xas_alloc lib/xarray.c:375 [inline] xas_create+0x111f/0x1760 lib/xarray.c:677 xas_store+0xa3/0x19e0 lib/xarray.c:787 shmem_add_to_page_cache+0xa80/0x1b80 mm/shmem.c:805 shmem_get_folio_gfp+0x1037/0x2b40 mm/shmem.c:2071 shmem_get_folio mm/shmem.c:2164 [inline] shmem_write_begin+0xf2/0x430 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+0x29f/0x6d0 fs/read_write.c:517 dump_emit_page fs/coredump.c:958 [inline] dump_user_range+0x418/0x840 fs/coredump.c:985 elf_core_dump+0x320e/0x37c0 fs/binfmt_elf.c:2184 do_coredump+0x1791/0x24a0 fs/coredump.c:834 get_signal+0x10da/0x1390 kernel/signal.c:2901 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:318 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 *** 5 locks held by syz.3.2406/15118: #0: ffff88805d612418 (sb_writers#5){.+.+}-{0:0}, at: do_coredump+0x1774/0x24a0 fs/coredump.c:833 #1: ffff888053378308 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff888053378308 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:2873 #2: ffff8880533783f0 (&xa->xa_lock#8){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #2: ffff8880533783f0 (&xa->xa_lock#8){..-.}-{2:2}, at: shmem_add_to_page_cache+0xa06/0x1b80 mm/shmem.c:796 #3: ffff8880b8e37da8 (stock_lock){-.-.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #3: ffff8880b8e37da8 (stock_lock){-.-.}-{2:2}, at: mod_objcg_state+0x101/0x8c0 mm/memcontrol.c:3203 #4: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #4: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #4: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xc3/0x6c0 kernel/trace/bpf_trace.c:142 stack backtrace: CPU: 0 PID: 15118 Comm: syz.3.2406 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: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_01ffad9a3ed37586+0x4d/0x51 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:606 [inline] bpf_prog_run include/linux/filter.h:624 [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+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 mod_objcg_state+0x2c4/0x8c0 mm/memcontrol.c:3223 memcg_slab_post_alloc_hook mm/slab.h:544 [inline] slab_post_alloc_hook+0x358/0x4d0 mm/slab.h:778 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc_lru+0x175/0x2b0 mm/slub.c:3526 xas_alloc lib/xarray.c:375 [inline] xas_create+0x111f/0x1760 lib/xarray.c:677 xas_store+0xa3/0x19e0 lib/xarray.c:787 shmem_add_to_page_cache+0xa80/0x1b80 mm/shmem.c:805 shmem_get_folio_gfp+0x1037/0x2b40 mm/shmem.c:2071 shmem_get_folio mm/shmem.c:2164 [inline] shmem_write_begin+0xf2/0x430 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+0x29f/0x6d0 fs/read_write.c:517 dump_emit_page fs/coredump.c:958 [inline] dump_user_range+0x418/0x840 fs/coredump.c:985 elf_core_dump+0x320e/0x37c0 fs/binfmt_elf.c:2184 do_coredump+0x1791/0x24a0 fs/coredump.c:834 get_signal+0x10da/0x1390 kernel/signal.c:2901 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:318 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: 0033:0x7ffa9a99e161 Code: 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 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:00000000fffffeb0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007ffa9ac25fa0 RCX: 00007ffa9a99e159 RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400 RBP: 00007ffa9aa3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffa9ac26038 R14: 00007ffa9ac25fa0 R15: 00007fff6e3d1c28