====================================================== WARNING: possible circular locking dependency detected 5.15.171-syzkaller #0 Not tainted ------------------------------------------------------ syz.3.57/4374 is trying to acquire lock: ffff8880622b9db8 (&trie->lock){..-.}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 but task is already holding lock: ffff8880b9128098 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:946 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&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 -> #1 (krc.lock){....}-{2:2}: 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_66e4249390890395+0x1e8/0xfe8 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+0x19e/0x340 kernel/trace/bpf_trace.c:1915 trace_tlb_flush+0xed/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x748/0xa30 unuse_temporary_mm arch/x86/kernel/alternative.c:1041 [inline] __text_poke+0x764/0x9e0 arch/x86/kernel/alternative.c:1137 text_poke arch/x86/kernel/alternative.c:1178 [inline] text_poke_bp_batch+0x14c/0x930 arch/x86/kernel/alternative.c:1404 text_poke_flush arch/x86/kernel/alternative.c:1598 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1605 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 tracepoint_add_func+0x947/0x9d0 kernel/tracepoint.c:361 tracepoint_probe_register_prio_may_exist+0x11e/0x190 kernel/tracepoint.c:482 bpf_raw_tracepoint_open+0x65a/0x750 kernel/bpf/syscall.c:3113 __sys_bpf+0x468/0x670 kernel/bpf/syscall.c:4693 __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+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&trie->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_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_prog_1db1603a7cfa36fb+0x3d/0xbac 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 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x157/0x240 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 __alloc_pages+0x2e7/0x700 mm/page_alloc.c:5486 vm_area_alloc_pages mm/vmalloc.c:2868 [inline] __vmalloc_area_node mm/vmalloc.c:2924 [inline] __vmalloc_node_range+0x5ab/0x8c0 mm/vmalloc.c:3029 __vmalloc_node mm/vmalloc.c:3079 [inline] __vmalloc+0x75/0x80 mm/vmalloc.c:3093 pcpu_mem_zalloc mm/percpu.c:516 [inline] pcpu_alloc_chunk mm/percpu.c:1472 [inline] pcpu_create_chunk+0x318/0xba0 mm/percpu-vm.c:338 pcpu_alloc+0x749/0x17c0 mm/percpu.c:1834 bpf_map_alloc_percpu+0xdb/0x160 kernel/bpf/syscall.c:455 prealloc_init kernel/bpf/hashtab.c:335 [inline] htab_map_alloc+0xca2/0x15a0 kernel/bpf/hashtab.c:554 find_and_alloc_map kernel/bpf/syscall.c:127 [inline] map_create+0x446/0x2070 kernel/bpf/syscall.c:877 __sys_bpf+0x276/0x670 kernel/bpf/syscall.c:4633 __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+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: &trie->lock --> krc.lock --> &base->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(krc.lock); lock(&base->lock); lock(&trie->lock); *** DEADLOCK *** 4 locks held by syz.3.57/4374: #0: ffffffff8c9cb608 (pcpu_alloc_mutex){+.+.}-{3:3}, at: pcpu_alloc+0x24e/0x17c0 mm/percpu.c:1774 #1: ffffc90000dd0be0 ((&app->join_timer)#2){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline] #1: ffffc90000dd0be0 ((&app->join_timer)#2){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x560 kernel/time/timer.c:1441 #2: ffff8880b9128098 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:946 #3: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 1 PID: 4374 Comm: syz.3.57 Not tainted 5.15.171-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_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_prog_1db1603a7cfa36fb+0x3d/0xbac 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 call_timer_fn+0x16d/0x560 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x157/0x240 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:__alloc_pages+0x2e7/0x700 mm/page_alloc.c:5486 Code: 85 c0 0f 85 c0 01 00 00 41 0f b6 04 16 84 c0 0f 85 b7 02 00 00 44 8b 6c 24 50 48 8d 7c 24 60 48 83 c7 18 48 89 f8 48 c1 e8 03 <0f> b6 04 10 84 c0 0f 85 c2 02 00 00 8b 5c 24 78 0f 1f 44 00 00 65 RSP: 0018:ffffc9000116f8e0 EFLAGS: 00000a06 RAX: 1ffff9200022df2b RBX: ffffea00017fa680 RCX: ffffc9000116f903 RDX: dffffc0000000000 RSI: 0000000000002dc2 RDI: ffffc9000116f958 RBP: ffffc9000116f9f0 R08: dffffc0000000000 R09: ffffed10032ef79d R10: 0000000000000000 R11: dffffc0000000001 R12: ffffea00017fa680 R13: 0000000000102dc2 R14: 1ffff9200022df26 R15: 1ffff9200022df20 vm_area_alloc_pages mm/vmalloc.c:2868 [inline] __vmalloc_area_node mm/vmalloc.c:2924 [inline] __vmalloc_node_range+0x5ab/0x8c0 mm/vmalloc.c:3029 __vmalloc_node mm/vmalloc.c:3079 [inline] __vmalloc+0x75/0x80 mm/vmalloc.c:3093 pcpu_mem_zalloc mm/percpu.c:516 [inline] pcpu_alloc_chunk mm/percpu.c:1472 [inline] pcpu_create_chunk+0x318/0xba0 mm/percpu-vm.c:338 pcpu_alloc+0x749/0x17c0 mm/percpu.c:1834 bpf_map_alloc_percpu+0xdb/0x160 kernel/bpf/syscall.c:455 prealloc_init kernel/bpf/hashtab.c:335 [inline] htab_map_alloc+0xca2/0x15a0 kernel/bpf/hashtab.c:554 find_and_alloc_map kernel/bpf/syscall.c:127 [inline] map_create+0x446/0x2070 kernel/bpf/syscall.c:877 __sys_bpf+0x276/0x670 kernel/bpf/syscall.c:4633 __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+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f334777e719 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:00007f3345bf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f3347935f80 RCX: 00007f334777e719 RDX: 0000000000000048 RSI: 0000000020000840 RDI: 0000000000000000 RBP: 00007f33477f139e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3347935f80 R15: 00007ffd2203c288 ---------------- Code disassembly (best guess): 0: 85 c0 test %eax,%eax 2: 0f 85 c0 01 00 00 jne 0x1c8 8: 41 0f b6 04 16 movzbl (%r14,%rdx,1),%eax d: 84 c0 test %al,%al f: 0f 85 b7 02 00 00 jne 0x2cc 15: 44 8b 6c 24 50 mov 0x50(%rsp),%r13d 1a: 48 8d 7c 24 60 lea 0x60(%rsp),%rdi 1f: 48 83 c7 18 add $0x18,%rdi 23: 48 89 f8 mov %rdi,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 0f b6 04 10 movzbl (%rax,%rdx,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 c2 02 00 00 jne 0x2f8 36: 8b 5c 24 78 mov 0x78(%rsp),%ebx 3a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 3f: 65 gs