====================================================== WARNING: possible circular locking dependency detected 5.15.170-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.162/4849 is trying to acquire lock: ffff8880b9127e78 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline] ffff8880b9127e78 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline] ffff8880b9127e78 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597 but task is already holding lock: ffff88802ad281b8 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&trie->lock){....}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 bpf_dispatcher_xdp+0x195/0x1000 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1916 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x3ae/0x540 kernel/time/timer.c:586 internal_add_timer kernel/time/timer.c:611 [inline] __mod_timer+0xa60/0xeb0 kernel/time/timer.c:1062 schedule_timeout+0x1b4/0x300 kernel/time/timer.c:1913 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #1 (&base->lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x120/0x260 kernel/time/timer.c:946 __mod_timer+0x1d6/0xeb0 kernel/time/timer.c:1019 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1715 queue_delayed_work include/linux/workqueue.h:527 [inline] schedule_delayed_work include/linux/workqueue.h:631 [inline] kvfree_call_rcu+0x50e/0x8a0 kernel/rcu/tree.c:3625 rtnl_register_internal+0x443/0x530 net/core/rtnetlink.c:223 rtnl_register+0x32/0x70 net/core/rtnetlink.c:273 ip_rt_init+0x2e6/0x390 net/ipv4/route.c:3750 ip_init+0xa/0x20 net/ipv4/ip_output.c:1749 inet_init+0x27c/0x390 net/ipv4/af_inet.c:2009 do_one_initcall+0x22b/0x7a0 init/main.c:1302 do_initcall_level+0x157/0x210 init/main.c:1375 do_initcalls+0x49/0x90 init/main.c:1391 kernel_init_freeable+0x425/0x5c0 init/main.c:1615 kernel_init+0x19/0x290 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #0 (krc.lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline] kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597 trie_delete_elem+0x520/0x690 bpf_prog_8c8ab8634bca3061+0x3a/0x658 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1916 __bpf_trace_kmem_cache_free+0x99/0xc0 include/trace/events/kmem.h:138 trace_kmem_cache_free include/trace/events/kmem.h:138 [inline] kmem_cache_free+0x1ce/0x1f0 mm/slub.c:3516 adjust_va_to_fit_type mm/vmalloc.c:1336 [inline] __alloc_vmap_area mm/vmalloc.c:1452 [inline] alloc_vmap_area+0x16ae/0x19a0 mm/vmalloc.c:1543 __get_vm_area_node+0x16e/0x2f0 mm/vmalloc.c:2423 __vmalloc_node_range+0xe3/0x8c0 mm/vmalloc.c:3019 __vmalloc_node mm/vmalloc.c:3079 [inline] __vmalloc+0x75/0x80 mm/vmalloc.c:3093 bpf_prog_alloc_no_stats+0x33/0x2f0 kernel/bpf/core.c:90 bpf_prog_alloc+0x18/0x1d0 kernel/bpf/core.c:124 bpf_prog_create_from_user+0xa0/0x3d0 net/core/filter.c:1418 seccomp_prepare_filter kernel/seccomp.c:669 [inline] seccomp_prepare_user_filter kernel/seccomp.c:706 [inline] seccomp_set_mode_filter kernel/seccomp.c:1834 [inline] do_seccomp+0x8cf/0x1790 kernel/seccomp.c:1954 __do_sys_prctl kernel/sys.c:2380 [inline] __se_sys_prctl+0x919/0x2ab0 kernel/sys.c:2298 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: krc.lock --> &base->lock --> &trie->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&trie->lock); lock(&base->lock); lock(&trie->lock); lock(krc.lock); *** DEADLOCK *** 3 locks held by syz.1.162/4849: #0: ffffffff8c9dedf8 (free_vmap_area_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:363 [inline] #0: ffffffff8c9dedf8 (free_vmap_area_lock){+.+.}-{2:2}, at: preload_this_cpu_lock mm/vmalloc.c:1500 [inline] #0: ffffffff8c9dedf8 (free_vmap_area_lock){+.+.}-{2:2}, at: alloc_vmap_area+0x23c/0x19a0 mm/vmalloc.c:1542 #1: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #2: ffff88802ad281b8 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 stack backtrace: CPU: 1 PID: 4849 Comm: syz.1.162 Not tainted 5.15.170-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline] kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597 trie_delete_elem+0x520/0x690 bpf_prog_8c8ab8634bca3061+0x3a/0x658 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1916 __bpf_trace_kmem_cache_free+0x99/0xc0 include/trace/events/kmem.h:138 trace_kmem_cache_free include/trace/events/kmem.h:138 [inline] kmem_cache_free+0x1ce/0x1f0 mm/slub.c:3516 adjust_va_to_fit_type mm/vmalloc.c:1336 [inline] __alloc_vmap_area mm/vmalloc.c:1452 [inline] alloc_vmap_area+0x16ae/0x19a0 mm/vmalloc.c:1543 __get_vm_area_node+0x16e/0x2f0 mm/vmalloc.c:2423 __vmalloc_node_range+0xe3/0x8c0 mm/vmalloc.c:3019 __vmalloc_node mm/vmalloc.c:3079 [inline] __vmalloc+0x75/0x80 mm/vmalloc.c:3093 bpf_prog_alloc_no_stats+0x33/0x2f0 kernel/bpf/core.c:90 bpf_prog_alloc+0x18/0x1d0 kernel/bpf/core.c:124 bpf_prog_create_from_user+0xa0/0x3d0 net/core/filter.c:1418 seccomp_prepare_filter kernel/seccomp.c:669 [inline] seccomp_prepare_user_filter kernel/seccomp.c:706 [inline] seccomp_set_mode_filter kernel/seccomp.c:1834 [inline] do_seccomp+0x8cf/0x1790 kernel/seccomp.c:1954 __do_sys_prctl kernel/sys.c:2380 [inline] __se_sys_prctl+0x919/0x2ab0 kernel/sys.c:2298 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f9d21e11719 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:00007f9d20289038 EFLAGS: 00000246 ORIG_RAX: 000000000000009d RAX: ffffffffffffffda RBX: 00007f9d21fc8f80 RCX: 00007f9d21e11719 RDX: 0000000020000000 RSI: 0000000000000002 RDI: 0000000000000016 RBP: 00007f9d21e8439e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9d21fc8f80 R15: 00007fff817a8ba8