====================================================== WARNING: possible circular locking dependency detected 6.1.129-syzkaller #0 Not tainted ------------------------------------------------------ syz.8.699/6941 is trying to acquire lock: ffff8880b8f28118 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline] ffff8880b8f28118 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline] ffff8880b8f28118 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402 but task is already holding lock: ffff8880b8f28358 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x62d/0xee0 kernel/time/timer.c:1096 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:3789 ip_init+0xa/0x14 net/ipv4/ip_output.c:1770 inet_init+0x2ae/0x3c0 net/ipv4/af_inet.c:2033 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:545 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:1000 [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:2284 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324 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 tp_rcu_get_state kernel/tracepoint.c:53 [inline] tracepoint_remove_func kernel/tracepoint.c:426 [inline] tracepoint_probe_unregister+0x7b9/0x980 kernel/tracepoint.c:551 bpf_raw_tp_link_release+0x5f/0x80 kernel/bpf/syscall.c:3195 bpf_link_free kernel/bpf/syscall.c:2764 [inline] bpf_link_put+0x234/0x2c0 kernel/bpf/syscall.c:2790 bpf_link_release+0x37/0x40 kernel/bpf/syscall.c:2799 __fput+0x3f6/0x8d0 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 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 *** 5 locks held by syz.8.699/6941: #0: ffffffff8d375be8 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_unregister+0x2e/0x980 kernel/tracepoint.c:548 #1: ffffffff8d375a68 (tracepoint_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d375a68 (tracepoint_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #1: ffffffff8d375a68 (tracepoint_srcu){....}-{0:0}, at: srcu_gp_start_if_needed+0x17f/0x1080 kernel/rcu/srcutree.c:1094 #2: ffffffff8d3757a8 (tracepoint_srcu.lock){..-.}-{2:2}, at: spin_lock_irqsave_ssp_contention+0x106/0x440 kernel/rcu/srcutree.c:378 #3: ffff8880b8f28358 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x62d/0xee0 kernel/time/timer.c:1096 #4: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #4: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #4: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline] #4: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2324 stack backtrace: CPU: 1 PID: 6941 Comm: syz.8.699 Not tainted 6.1.129-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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:545 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:1000 [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:2284 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324 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 tp_rcu_get_state kernel/tracepoint.c:53 [inline] tracepoint_remove_func kernel/tracepoint.c:426 [inline] tracepoint_probe_unregister+0x7b9/0x980 kernel/tracepoint.c:551 bpf_raw_tp_link_release+0x5f/0x80 kernel/bpf/syscall.c:3195 bpf_link_free kernel/bpf/syscall.c:2764 [inline] bpf_link_put+0x234/0x2c0 kernel/bpf/syscall.c:2790 bpf_link_release+0x37/0x40 kernel/bpf/syscall.c:2799 __fput+0x3f6/0x8d0 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff2c658d169 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:00007fff032abb38 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ff2c67a7ba0 RCX: 00007ff2c658d169 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007ff2c67a7ba0 R08: 0000000000000074 R09: 00000006032abe2f R10: 00000000003ffd68 R11: 0000000000000246 R12: 0000000000045f47 R13: 00007ff2c67a6080 R14: ffffffffffffffff R15: 00007fff032abc50