====================================================== WARNING: possible circular locking dependency detected 6.1.142-syzkaller #0 Not tainted ------------------------------------------------------ syz.6.326/5487 is trying to acquire lock: ffff8880b8e281d8 (krc.lock){-.-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] ffff8880b8e281d8 (krc.lock){-.-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] ffff8880b8e281d8 (krc.lock){-.-.}-{2:2}, at: kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3402 but task is already holding lock: ffff8880b8e2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1756 [inline] ffff8880b8e2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x63a/0xd60 kernel/time/hrtimer.c:1816 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #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:180 [inline] hrtimer_start_range_ns+0xec/0xfc0 kernel/time/hrtimer.c:1351 hrtimer_start include/linux/hrtimer.h:421 [inline] run_page_cache_worker kernel/rcu/tree.c:3293 [inline] kvfree_call_rcu+0x6d0/0x870 kernel/rcu/tree.c:3404 rtnl_register_internal+0x489/0x590 net/core/rtnetlink.c:260 rtnl_register+0x2e/0x70 net/core/rtnetlink.c:310 ip_rt_init+0x323/0x3b5 net/ipv4/route.c:3793 ip_init+0xa/0x14 net/ipv4/ip_output.c:1771 inet_init+0x2bd/0x3cf net/ipv4/af_inet.c:2033 do_one_initcall+0x214/0x7a0 init/main.c:1298 do_initcall_level+0x137/0x1e4 init/main.c:1371 do_initcalls+0x4b/0x8a init/main.c:1387 kernel_init_freeable+0x3fa/0x5ac init/main.c:1626 kernel_init+0x19/0x1b0 init/main.c:1514 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (krc.lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3402 trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545 bpf_prog_5186c38a4019a4cb+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1001 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:504 [inline] enqueue_hrtimer+0x36e/0x3f0 kernel/time/hrtimer.c:1110 __run_hrtimer kernel/time/hrtimer.c:1769 [inline] __hrtimer_run_queues+0x68e/0xd60 kernel/time/hrtimer.c:1816 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] csd_lock_wait kernel/smp.c:424 [inline] smp_call_function_many_cond+0xe7b/0x1270 kernel/smp.c:998 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1574 [inline] text_poke_bp_batch+0x2b0/0x7d0 arch/x86/kernel/alternative.c:1774 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 tracepoint_add_func+0x83b/0x9a0 kernel/tracepoint.c:361 tracepoint_probe_register_prio_may_exist+0x5c/0x90 kernel/tracepoint.c:482 bpf_raw_tp_link_attach+0x3d1/0x550 kernel/bpf/syscall.c:3387 bpf_raw_tracepoint_open+0x194/0x200 kernel/bpf/syscall.c:3414 __sys_bpf+0x4e9/0x6d0 kernel/bpf/syscall.c:5062 __do_sys_bpf kernel/bpf/syscall.c:5124 [inline] __se_sys_bpf kernel/bpf/syscall.c:5122 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 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(hrtimer_bases.lock); lock(krc.lock); lock(hrtimer_bases.lock); lock(krc.lock); *** DEADLOCK *** 6 locks held by syz.6.326/5487: #0: ffffffff8c971f08 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_register_prio_may_exist+0x40/0x90 kernel/tracepoint.c:478 #1: ffffffff8c7c78f0 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0xe/0x20 kernel/jump_label.c:219 #2: ffffffff8c9c89a8 (jump_label_mutex){+.+.}-{3:3}, at: jump_label_lock kernel/jump_label.c:27 [inline] #2: ffffffff8c9c89a8 (jump_label_mutex){+.+.}-{3:3}, at: static_key_enable_cpuslocked+0xc2/0x240 kernel/jump_label.c:204 #3: ffffffff8c7dc768 (text_mutex){+.+.}-{3:3}, at: arch_jump_label_transform_apply+0xe/0x20 arch/x86/kernel/jump_label.c:145 #4: ffff8880b8e2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1756 [inline] #4: ffff8880b8e2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x63a/0xd60 kernel/time/hrtimer.c:1816 #5: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #5: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #5: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] #5: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xda/0x3b0 kernel/trace/bpf_trace.c:2324 stack backtrace: CPU: 0 PID: 5487 Comm: syz.6.326 Not tainted 6.1.142-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3402 trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545 bpf_prog_5186c38a4019a4cb+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1001 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:504 [inline] enqueue_hrtimer+0x36e/0x3f0 kernel/time/hrtimer.c:1110 __run_hrtimer kernel/time/hrtimer.c:1769 [inline] __hrtimer_run_queues+0x68e/0xd60 kernel/time/hrtimer.c:1816 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0xe7b/0x1270 kernel/smp.c:998 Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 6d e9 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 f9 e5 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 de e5 0a RSP: 0018:ffffc900038c77e0 EFLAGS: 00000287 RAX: ffffffff8175f1a2 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc9001e363000 RSI: 0000000000003202 RDI: 0000000000003203 RBP: ffffc900038c7940 R08: dffffc0000000000 R09: fffffbfff2117249 R10: fffffbfff2117249 R11: 1ffffffff2117248 R12: 1ffff110171e81c1 R13: ffff8880b8e3bb40 R14: 0000000000000001 R15: ffff8880b8f40e08 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1574 [inline] text_poke_bp_batch+0x2b0/0x7d0 arch/x86/kernel/alternative.c:1774 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 tracepoint_add_func+0x83b/0x9a0 kernel/tracepoint.c:361 tracepoint_probe_register_prio_may_exist+0x5c/0x90 kernel/tracepoint.c:482 bpf_raw_tp_link_attach+0x3d1/0x550 kernel/bpf/syscall.c:3387 bpf_raw_tracepoint_open+0x194/0x200 kernel/bpf/syscall.c:3414 __sys_bpf+0x4e9/0x6d0 kernel/bpf/syscall.c:5062 __do_sys_bpf kernel/bpf/syscall.c:5124 [inline] __se_sys_bpf kernel/bpf/syscall.c:5122 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f35bb18e929 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:00007f35bbf7d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f35bb3b5fa0 RCX: 00007f35bb18e929 RDX: 000000000000003d RSI: 0000200000000000 RDI: 0000000000000011 RBP: 00007f35bb210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f35bb3b5fa0 R15: 00007fff9058fbd8 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 00 add %al,(%rax) 2: 41 8b 1f mov (%r15),%ebx 5: 89 de mov %ebx,%esi 7: 83 e6 01 and $0x1,%esi a: 31 ff xor %edi,%edi c: e8 6d e9 0a 00 call 0xae97e 11: 83 e3 01 and $0x1,%ebx 14: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx 1b: fc ff df 1e: 75 07 jne 0x27 20: e8 f9 e5 0a 00 call 0xae61e 25: eb 37 jmp 0x5e 27: f3 90 pause * 29: 41 0f b6 04 1c movzbl (%r12,%rbx,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 75 10 jne 0x42 32: 41 f7 07 01 00 00 00 testl $0x1,(%r15) 39: 74 1e je 0x59 3b: e8 .byte 0xe8 3c: de e5 fsubp %st,%st(5) 3e: 0a .byte 0xa