====================================================== WARNING: possible circular locking dependency detected 6.6.100-syzkaller #0 Not tainted ------------------------------------------------------ syz.0.1215/8688 is trying to acquire lock: ffff88801eab8a38 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 but task is already holding lock: ffffffff8d3ec238 (pool_lock#2){-.-.}-{2:2}, at: __stack_depot_save+0x1a8/0x630 lib/stackdepot.c:415 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (pool_lock#2){-.-.}-{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 __stack_depot_save+0x1a8/0x630 lib/stackdepot.c:415 save_stack+0x105/0x1f0 mm/page_owner.c:129 __set_page_owner+0x1d/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 __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+0x660/0x720 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_ae0c3e605f35524c+0x45/0x49 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 __stack_depot_save+0x1a8/0x630 lib/stackdepot.c:415 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x5f/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509 kmem_cache_zalloc include/linux/slab.h:711 [inline] fill_pool lib/debugobjects.c:169 [inline] debug_objects_fill_pool+0x344/0x6b0 lib/debugobjects.c:616 debug_object_activate+0x36/0x4b0 lib/debugobjects.c:705 debug_rcu_head_queue kernel/rcu/rcu.h:227 [inline] __call_rcu_common kernel/rcu/tree.c:2706 [inline] call_rcu+0xab/0x930 kernel/rcu/tree.c:2837 call_rcu_hurry include/linux/rcupdate.h:117 [inline] rcu_sync_call kernel/rcu/sync.c:47 [inline] rcu_sync_exit+0xce/0x1b0 kernel/rcu/sync.c:177 cgroup_attach_unlock kernel/cgroup/cgroup.c:2403 [inline] cgroup_procs_write_finish+0xb8/0x430 kernel/cgroup/cgroup.c:2941 __cgroup1_procs_write+0x2f0/0x3c0 kernel/cgroup/cgroup-v1.c:525 cgroup_file_write+0x2fc/0x660 kernel/cgroup/cgroup.c:4066 kernfs_fop_write_iter+0x37d/0x4d0 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x43b/0x940 fs/read_write.c:584 ksys_write+0x147/0x250 fs/read_write.c:637 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: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(pool_lock#2); lock(&trie->lock); lock(pool_lock#2); lock(&trie->lock); *** DEADLOCK *** 9 locks held by syz.0.1215/8688: #0: ffff8880244fd748 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1042 #1: ffff88807900c418 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x20e/0x940 fs/read_write.c:580 #2: ffff888025ad2488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e9/0x4d0 fs/kernfs/file.c:325 #3: ffffffff8cd59ac8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline] #3: ffffffff8cd59ac8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xf2/0x230 kernel/cgroup/cgroup.c:1654 #4: ffffffff8cbcafd0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2391 [inline] #4: ffffffff8cbcafd0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x187/0x600 kernel/cgroup/cgroup.c:2895 #5: ffffffff8cd59c00 (cgroup_threadgroup_rwsem.rss.gp_wait.lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline] #5: ffffffff8cd59c00 (cgroup_threadgroup_rwsem.rss.gp_wait.lock){..-.}-{2:2}, at: rcu_sync_exit+0x68/0x1b0 kernel/rcu/sync.c:173 #6: ffffffff8d3d63c0 (fill_pool_map-wait-type-override){+.+.}-{3:3}, at: debug_objects_fill_pool+0x73/0x6b0 lib/debugobjects.c:615 #7: ffffffff8d3ec238 (pool_lock#2){-.-.}-{2:2}, at: __stack_depot_save+0x1a8/0x630 lib/stackdepot.c:415 #8: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #8: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #8: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #8: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361 stack backtrace: CPU: 0 PID: 8688 Comm: syz.0.1215 Not tainted 6.6.100-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_ae0c3e605f35524c+0x45/0x49 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 __stack_depot_save+0x1a8/0x630 lib/stackdepot.c:415 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x5f/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509 kmem_cache_zalloc include/linux/slab.h:711 [inline] fill_pool lib/debugobjects.c:169 [inline] debug_objects_fill_pool+0x344/0x6b0 lib/debugobjects.c:616 debug_object_activate+0x36/0x4b0 lib/debugobjects.c:705 debug_rcu_head_queue kernel/rcu/rcu.h:227 [inline] __call_rcu_common kernel/rcu/tree.c:2706 [inline] call_rcu+0xab/0x930 kernel/rcu/tree.c:2837 call_rcu_hurry include/linux/rcupdate.h:117 [inline] rcu_sync_call kernel/rcu/sync.c:47 [inline] rcu_sync_exit+0xce/0x1b0 kernel/rcu/sync.c:177 cgroup_attach_unlock kernel/cgroup/cgroup.c:2403 [inline] cgroup_procs_write_finish+0xb8/0x430 kernel/cgroup/cgroup.c:2941 __cgroup1_procs_write+0x2f0/0x3c0 kernel/cgroup/cgroup-v1.c:525 cgroup_file_write+0x2fc/0x660 kernel/cgroup/cgroup.c:4066 kernfs_fop_write_iter+0x37d/0x4d0 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x43b/0x940 fs/read_write.c:584 ksys_write+0x147/0x250 fs/read_write.c:637 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: 0033:0x7f17bfb8e9a9 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:00007f17c095a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f17bfdb5fa0 RCX: 00007f17bfb8e9a9 RDX: 0000000000000012 RSI: 0000200000000880 RDI: 000000000000000c RBP: 00007f17bfc10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f17bfdb5fa0 R15: 00007ffd836b9958 netlink: 'syz.0.1215': attribute type 2 has an invalid length. netlink: 164 bytes leftover after parsing attributes in process `syz.0.1215'.