====================================================== WARNING: possible circular locking dependency detected 5.15.184-syzkaller #0 Not tainted ------------------------------------------------------ syz.2.12/4280 is trying to acquire lock: ffff8880b9027e78 (krc.lock){-.-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline] ffff8880b9027e78 (krc.lock){-.-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline] ffff8880b9027e78 (krc.lock){-.-.}-{2:2}, at: kvfree_call_rcu+0x186/0x7c0 kernel/rcu/tree.c:3597 but task is already holding lock: ffff88807d7889b8 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&trie->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 bpf_prog_5186c38a4019a4cb+0x42/0xb08 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_run2+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:466 [inline] enqueue_hrtimer+0x314/0x370 kernel/time/hrtimer.c:1074 __run_hrtimer kernel/time/hrtimer.c:1707 [inline] __hrtimer_run_queues+0x65a/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 expire_timers kernel/time/timer.c:1495 [inline] __run_timers+0x516/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:641 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 preempt_schedule_irq+0xac/0x150 kernel/sched/core.c:6780 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 lock_is_held_type+0x3/0x190 kernel/locking/lockdep.c:5651 lock_is_held include/linux/lockdep.h:287 [inline] ___might_sleep+0xa3/0x600 kernel/sched/core.c:9605 might_alloc include/linux/sched/mm.h:209 [inline] slab_pre_alloc_hook+0x42/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] slab_alloc mm/slub.c:3228 [inline] __kmalloc_track_caller+0x69/0x330 mm/slub.c:4925 __do_krealloc mm/slab_common.c:1244 [inline] krealloc+0x5a/0xf0 mm/slab_common.c:1277 push_jmp_history kernel/bpf/verifier.c:2125 [inline] is_state_visited kernel/bpf/verifier.c:11061 [inline] do_check+0x2d3d/0xeac0 kernel/bpf/verifier.c:11201 do_check_common+0xe67/0x16c0 kernel/bpf/verifier.c:13485 do_check_main kernel/bpf/verifier.c:13548 [inline] bpf_check+0x31f3/0xf090 kernel/bpf/verifier.c:14119 bpf_prog_load+0x1043/0x1550 kernel/bpf/syscall.c:2348 __sys_bpf+0x4c2/0x670 kernel/bpf/syscall.c:4651 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (hrtimer_bases.lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:168 [inline] hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1289 hrtimer_start include/linux/hrtimer.h:420 [inline] run_page_cache_worker kernel/rcu/tree.c:3488 [inline] kvfree_call_rcu+0x60d/0x7c0 kernel/rcu/tree.c:3599 rtnl_register_internal+0x44e/0x540 net/core/rtnetlink.c:223 rtnl_register+0x2e/0x70 net/core/rtnetlink.c:273 ip_rt_init+0x2e0/0x3a0 net/ipv4/route.c:3791 ip_init+0xa/0x20 net/ipv4/ip_output.c:1749 inet_init+0x28b/0x3a0 net/ipv4/af_inet.c:2007 do_one_initcall+0x1ee/0x680 init/main.c:1302 do_initcall_level+0x137/0x1f0 init/main.c:1375 do_initcalls+0x4b/0x90 init/main.c:1391 kernel_init_freeable+0x3ce/0x560 init/main.c:1615 kernel_init+0x19/0x1b0 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 kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 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+0x186/0x7c0 kernel/rcu/tree.c:3597 trie_delete_elem+0x58c/0x710 kernel/bpf/lpm_trie.c:-1 bpf_prog_5186c38a4019a4cb+0x42/0xb08 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_run2+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:466 [inline] enqueue_hrtimer+0x314/0x370 kernel/time/hrtimer.c:1074 __run_hrtimer kernel/time/hrtimer.c:1707 [inline] __hrtimer_run_queues+0x65a/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 expire_timers kernel/time/timer.c:1495 [inline] __run_timers+0x516/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:641 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 preempt_schedule_irq+0xac/0x150 kernel/sched/core.c:6780 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 lock_is_held_type+0x3/0x190 kernel/locking/lockdep.c:5651 lock_is_held include/linux/lockdep.h:287 [inline] ___might_sleep+0xa3/0x600 kernel/sched/core.c:9605 might_alloc include/linux/sched/mm.h:209 [inline] slab_pre_alloc_hook+0x42/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] slab_alloc mm/slub.c:3228 [inline] __kmalloc_track_caller+0x69/0x330 mm/slub.c:4925 __do_krealloc mm/slab_common.c:1244 [inline] krealloc+0x5a/0xf0 mm/slab_common.c:1277 push_jmp_history kernel/bpf/verifier.c:2125 [inline] is_state_visited kernel/bpf/verifier.c:11061 [inline] do_check+0x2d3d/0xeac0 kernel/bpf/verifier.c:11201 do_check_common+0xe67/0x16c0 kernel/bpf/verifier.c:13485 do_check_main kernel/bpf/verifier.c:13548 [inline] bpf_check+0x31f3/0xf090 kernel/bpf/verifier.c:14119 bpf_prog_load+0x1043/0x1550 kernel/bpf/syscall.c:2348 __sys_bpf+0x4c2/0x670 kernel/bpf/syscall.c:4651 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 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 --> hrtimer_bases.lock --> &trie->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&trie->lock); lock(hrtimer_bases.lock); lock(&trie->lock); lock(krc.lock); *** DEADLOCK *** 3 locks held by syz.2.12/4280: #0: ffff8880b902a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1694 [inline] #0: ffff8880b902a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5ff/0xc40 kernel/time/hrtimer.c:1754 #1: ffffffff8c11c060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #2: ffff88807d7889b8 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 stack backtrace: CPU: 0 PID: 4280 Comm: syz.2.12 Not tainted 5.15.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 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 kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 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+0x186/0x7c0 kernel/rcu/tree.c:3597 trie_delete_elem+0x58c/0x710 kernel/bpf/lpm_trie.c:-1 bpf_prog_5186c38a4019a4cb+0x42/0xb08 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_run2+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:466 [inline] enqueue_hrtimer+0x314/0x370 kernel/time/hrtimer.c:1074 __run_hrtimer kernel/time/hrtimer.c:1707 [inline] __hrtimer_run_queues+0x65a/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ce d9 b1 f7 48 89 df e8 96 ae b2 f7 e8 d1 52 d3 f7 fb bf 01 00 00 00 c6 d2 a6 f7 65 8b 05 37 e3 57 76 85 c0 74 02 5b c3 e8 e4 ed 55 RSP: 0018:ffffc90000007c90 EFLAGS: 00000286 RAX: c16f3f7bdd7f3a00 RBX: ffff8880b9028080 RCX: c16f3f7bdd7f3a00 RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001 RBP: ffffc90000007df0 R08: dffffc0000000000 R09: ffffed1017205011 R10: ffffed1017205011 R11: 1ffff11017205010 R12: ffff8880b9028080 R13: 1ffff11017205018 R14: ffffffff96416020 R15: ffffc90000007d40 expire_timers kernel/time/timer.c:1495 [inline] __run_timers+0x516/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:641 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:preempt_schedule_irq+0xac/0x150 kernel/sched/core.c:6780 Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 70 bf 01 00 00 00 e8 bf f4 a7 f7 e8 4a 76 d4 f7 fb bf 01 00 00 00 cf b5 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24 RSP: 0018:ffffc900032bef20 EFLAGS: 00000282 RAX: c16f3f7bdd7f3a00 RBX: 0000000000000000 RCX: c16f3f7bdd7f3a00 RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001 RBP: ffffc900032befc0 R08: ffffffff8eeb0008 R09: ffffffff8eeb0018 R10: ffffffff8eeb0010 R11: ffffffff8eeb0003 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000657de4 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_is_held_type+0x3/0x190 kernel/locking/lockdep.c:5651 Code: 00 75 d6 48 c7 c7 60 10 0b 8a 48 c7 c6 a0 10 0b 8a e8 e1 38 f5 ff 0f 0b eb bf e8 98 fd ff ff 0f 1f 84 00 00 00 00 00 55 41 57 <41> 56 41 55 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 RSP: 0018:ffffc900032bf088 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 1ffff92000657e1c RCX: ffff888022458000 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8c11c0c0 RBP: ffffc900032bf1b0 R08: dffffc0000000000 R09: fffffbfff1ad1556 R10: fffffbfff1ad1556 R11: 1ffffffff1ad1555 R12: dffffc0000000000 R13: ffff88801f082670 R14: ffff888016841640 R15: 0000000000000001 lock_is_held include/linux/lockdep.h:287 [inline] ___might_sleep+0xa3/0x600 kernel/sched/core.c:9605 might_alloc include/linux/sched/mm.h:209 [inline] slab_pre_alloc_hook+0x42/0xc0 mm/slab.h:492 slab_alloc_node mm/slub.c:3134 [inline] slab_alloc mm/slub.c:3228 [inline] __kmalloc_track_caller+0x69/0x330 mm/slub.c:4925 __do_krealloc mm/slab_common.c:1244 [inline] krealloc+0x5a/0xf0 mm/slab_common.c:1277 push_jmp_history kernel/bpf/verifier.c:2125 [inline] is_state_visited kernel/bpf/verifier.c:11061 [inline] do_check+0x2d3d/0xeac0 kernel/bpf/verifier.c:11201 do_check_common+0xe67/0x16c0 kernel/bpf/verifier.c:13485 do_check_main kernel/bpf/verifier.c:13548 [inline] bpf_check+0x31f3/0xf090 kernel/bpf/verifier.c:14119 bpf_prog_load+0x1043/0x1550 kernel/bpf/syscall.c:2348 __sys_bpf+0x4c2/0x670 kernel/bpf/syscall.c:4651 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f307e2b4969 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:00007f307c11c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f307e4dbfa0 RCX: 00007f307e2b4969 RDX: 0000000000000080 RSI: 0000200000003480 RDI: 0000000000000005 RBP: 00007f307e336ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f307e4dbfa0 R15: 00007ffe97b96128 ---------------- Code disassembly (best guess): 0: f6 ff idiv %bh 2: 0f 1f 00 nopl (%rax) 5: 53 push %rbx 6: 48 89 fb mov %rdi,%rbx 9: 48 83 c7 18 add $0x18,%rdi d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 12: e8 ce d9 b1 f7 call 0xf7b1d9e5 17: 48 89 df mov %rbx,%rdi 1a: e8 96 ae b2 f7 call 0xf7b2aeb5 1f: e8 d1 52 d3 f7 call 0xf7d352f5 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 c6 d2 a6 f7 call 0xf7a6d2f5 <-- trapping instruction 2f: 65 8b 05 37 e3 57 76 mov %gs:0x7657e337(%rip),%eax # 0x7657e36d 36: 85 c0 test %eax,%eax 38: 74 02 je 0x3c 3a: 5b pop %rbx 3b: c3 ret 3c: e8 .byte 0xe8 3d: e4 ed in $0xed,%al 3f: 55 push %rbp