====================================================== WARNING: possible circular locking dependency detected 6.1.112-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.803/5795 is trying to acquire lock: ffff8880b8e28118 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] ffff8880b8e28118 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] ffff8880b8e28118 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 but task is already holding lock: ffff8880b8e28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&base->lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __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:999 __mod_timer+0x1cb/0xee0 kernel/time/timer.c:1072 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] schedule_delayed_monitor_work kernel/rcu/tree.c:3172 [inline] kvfree_call_rcu+0x520/0x8c0 kernel/rcu/tree.c:3428 rtnl_register_internal+0x489/0x580 net/core/rtnetlink.c:260 rtnl_register+0x32/0x70 net/core/rtnetlink.c:310 ip_rt_init+0x335/0x3c7 net/ipv4/route.c:3763 ip_init+0xa/0x14 net/ipv4/ip_output.c:1767 inet_init+0x2ae/0x3c0 net/ipv4/af_inet.c:2035 do_one_initcall+0x265/0x8f0 init/main.c:1298 do_initcall_level+0x157/0x207 init/main.c:1371 do_initcalls+0x49/0x86 init/main.c:1387 kernel_init_freeable+0x45c/0x60f init/main.c:1626 kernel_init+0x19/0x290 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+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 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+0x1b2/0x8c0 kernel/rcu/tree.c:3402 trie_delete_elem+0x53a/0x690 kernel/bpf/lpm_trie.c:532 bpf_prog_d46ba5bef82912c0+0x3d/0x41 bpf_dispatcher_nop_func include/linux/bpf.h:989 [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:2273 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2313 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 __mod_timer+0x92b/0xee0 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] srcu_funnel_gp_start kernel/rcu/srcutree.c:951 [inline] srcu_gp_start_if_needed+0xce5/0x1080 kernel/rcu/srcutree.c:1151 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0xade/0x1820 kernel/rcu/tree.c:2557 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571 __do_softirq kernel/softirq.c:605 [inline] invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 console_emit_next_record+0xd67/0x1000 kernel/printk/printk.c:2786 console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303 _printk+0xd1/0x111 kernel/printk/printk.c:2328 bpf_get_probe_write_proto+0x96/0xb0 kernel/trace/bpf_trace.c:365 check_helper_call+0x25e/0x73d0 kernel/bpf/verifier.c:7506 do_check kernel/bpf/verifier.c:12679 [inline] do_check_common+0x88f4/0xca90 kernel/bpf/verifier.c:14953 do_check_main kernel/bpf/verifier.c:15016 [inline] bpf_check+0x65a2/0x16140 kernel/bpf/verifier.c:15593 bpf_prog_load+0x12df/0x1bb0 kernel/bpf/syscall.c:2646 __sys_bpf+0x382/0x6c0 kernel/bpf/syscall.c:5020 __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+0x3b/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(&base->lock); lock(krc.lock); lock(&base->lock); lock(krc.lock); *** DEADLOCK *** 6 locks held by syz.1.803/5795: #0: ffffffff8d207220 (console_lock){+.+.}-{0:0}, at: _printk+0xd1/0x111 kernel/printk/printk.c:2328 #1: ffffffff8d32b0c0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d32b0c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2291 [inline] #1: ffffffff8d32b0c0 (rcu_callback){....}-{0:0}, at: rcu_core+0xa6b/0x1820 kernel/rcu/tree.c:2557 #2: ffffffff8d3717e8 (tracepoint_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #2: ffffffff8d3717e8 (tracepoint_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #2: ffffffff8d3717e8 (tracepoint_srcu){....}-{0:0}, at: srcu_gp_start_if_needed+0x17f/0x1080 kernel/rcu/srcutree.c:1094 #3: ffffffff8d371528 (tracepoint_srcu.lock){....}-{2:2}, at: spin_lock_irqsave_ssp_contention+0x106/0x440 kernel/rcu/srcutree.c:378 #4: ffff8880b8e28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 #5: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #5: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #5: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] #5: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2313 stack backtrace: CPU: 0 PID: 5795 Comm: syz.1.803 Not tainted 6.1.112-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+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 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+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 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+0x1b2/0x8c0 kernel/rcu/tree.c:3402 trie_delete_elem+0x53a/0x690 kernel/bpf/lpm_trie.c:532 bpf_prog_d46ba5bef82912c0+0x3d/0x41 bpf_dispatcher_nop_func include/linux/bpf.h:989 [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:2273 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2313 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 __mod_timer+0x92b/0xee0 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] srcu_funnel_gp_start kernel/rcu/srcutree.c:951 [inline] srcu_gp_start_if_needed+0xce5/0x1080 kernel/rcu/srcutree.c:1151 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0xade/0x1820 kernel/rcu/tree.c:2557 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571 __do_softirq kernel/softirq.c:605 [inline] invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:console_emit_next_record+0xd67/0x1000 kernel/printk/printk.c:2786 Code: 29 1c 00 44 0f b6 74 24 1f 48 83 7c 24 30 00 75 07 e8 3d 29 1c 00 eb 06 e8 36 29 1c 00 fb 48 c7 84 24 a0 00 00 00 0e 36 e0 45 <43> c7 04 2c 00 00 00 00 4b c7 44 2c 0a 00 00 00 00 4b c7 44 2c 12 RSP: 0018:ffffc9000372e680 EFLAGS: 00000287 RAX: ffffffff816e860a RBX: ffffffff816e834c RCX: 0000000000040000 RDX: ffffc90003fb2000 RSI: 0000000000003a98 RDI: 0000000000003a99 RBP: ffffc9000372e930 R08: ffffffff816e85e2 R09: fffffbfff223ba45 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff920006e5ce4 R14: 0000000000000001 R15: 0000000000000000 console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303 _printk+0xd1/0x111 kernel/printk/printk.c:2328 bpf_get_probe_write_proto+0x96/0xb0 kernel/trace/bpf_trace.c:365 check_helper_call+0x25e/0x73d0 kernel/bpf/verifier.c:7506 do_check kernel/bpf/verifier.c:12679 [inline] do_check_common+0x88f4/0xca90 kernel/bpf/verifier.c:14953 do_check_main kernel/bpf/verifier.c:15016 [inline] bpf_check+0x65a2/0x16140 kernel/bpf/verifier.c:15593 bpf_prog_load+0x12df/0x1bb0 kernel/bpf/syscall.c:2646 __sys_bpf+0x382/0x6c0 kernel/bpf/syscall.c:5020 __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+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f63d597dff9 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:00007f63d6775038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f63d5b35f80 RCX: 00007f63d597dff9 RDX: 0000000000000090 RSI: 00000000200000c0 RDI: 0000000000000005 RBP: 00007f63d59f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f63d5b35f80 R15: 00007fff5cca1d98 ---------------- Code disassembly (best guess): 0: 29 1c 00 sub %ebx,(%rax,%rax,1) 3: 44 0f b6 74 24 1f movzbl 0x1f(%rsp),%r14d 9: 48 83 7c 24 30 00 cmpq $0x0,0x30(%rsp) f: 75 07 jne 0x18 11: e8 3d 29 1c 00 call 0x1c2953 16: eb 06 jmp 0x1e 18: e8 36 29 1c 00 call 0x1c2953 1d: fb sti 1e: 48 c7 84 24 a0 00 00 movq $0x45e0360e,0xa0(%rsp) 25: 00 0e 36 e0 45 * 2a: 43 c7 04 2c 00 00 00 movl $0x0,(%r12,%r13,1) <-- trapping instruction 31: 00 32: 4b c7 44 2c 0a 00 00 movq $0x0,0xa(%r12,%r13,1) 39: 00 00 3b: 4b rex.WXB 3c: c7 .byte 0xc7 3d: 44 2c 12 rex.R sub $0x12,%al