====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc2-syzkaller-00736-g4ff5747158f3 #0 Not tainted ------------------------------------------------------ syz-executor.2/7287 is trying to acquire lock: ffff8880b9529430 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3298 [inline] ffff8880b9529430 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] ffff8880b9529430 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x18a/0x790 kernel/rcu/tree.c:3782 but task is already holding lock: ffff8880b952a718 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&base->lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 __mod_timer+0x1ca/0xeb0 kernel/time/timer.c:1132 queue_delayed_work_on+0x1ca/0x390 kernel/workqueue.c:2572 kvfree_call_rcu+0x47f/0x790 kernel/rcu/tree.c:3810 rtnl_register_internal+0x482/0x590 net/core/rtnetlink.c:265 rtnl_register+0x36/0x80 net/core/rtnetlink.c:315 ip_rt_init+0x2bd/0x360 net/ipv4/route.c:3694 ip_init+0xe/0x20 net/ipv4/ip_output.c:1667 inet_init+0x3d8/0x580 net/ipv4/af_inet.c:1983 do_one_initcall+0x248/0x880 init/main.c:1267 do_initcall_level+0x157/0x210 init/main.c:1329 do_initcalls+0x3f/0x80 init/main.c:1345 kernel_init_freeable+0x435/0x5d0 init/main.c:1578 kernel_init+0x1d/0x2b0 init/main.c:1467 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (krc.lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3298 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] kvfree_call_rcu+0x18a/0x790 kernel/rcu/tree.c:3782 trie_delete_elem+0x546/0x6a0 kernel/bpf/lpm_trie.c:540 bpf_prog_7dc2717de7fcbdae+0x45/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 __traceiter_timer_start+0x75/0xc0 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x3ce/0x570 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0xa0e/0xeb0 kernel/time/timer.c:1183 queue_delayed_work_on+0x1ca/0x390 kernel/workqueue.c:2572 queue_delayed_work include/linux/workqueue.h:636 [inline] srcu_funnel_gp_start kernel/rcu/srcutree.c:1058 [inline] srcu_gp_start_if_needed+0xe65/0x11e0 kernel/rcu/srcutree.c:1302 tp_rcu_get_state kernel/tracepoint.c:53 [inline] tracepoint_remove_func kernel/tracepoint.c:426 [inline] tracepoint_probe_unregister+0x7c5/0x990 kernel/tracepoint.c:551 bpf_raw_tp_link_release+0x45/0x70 kernel/bpf/syscall.c:3541 bpf_link_free+0xf5/0x250 kernel/bpf/syscall.c:3067 bpf_link_put_direct kernel/bpf/syscall.c:3107 [inline] bpf_link_release+0x7b/0x90 kernel/bpf/syscall.c:3114 __fput+0x406/0x8b0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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 *** 4 locks held by syz-executor.2/7287: #0: ffffffff8e3809e8 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_unregister+0x32/0x990 kernel/tracepoint.c:548 #1: ffffffff8e380588 (tracepoint_srcu_srcu_usage.lock){....}-{2:2}, at: spin_lock_irqsave_ssp_contention+0x12a/0x510 kernel/rcu/srcutree.c:389 #2: ffff8880b952a718 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 #3: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #3: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2447 stack backtrace: CPU: 1 PID: 7287 Comm: syz-executor.2 Not tainted 6.10.0-rc2-syzkaller-00736-g4ff5747158f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3298 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3697 [inline] kvfree_call_rcu+0x18a/0x790 kernel/rcu/tree.c:3782 trie_delete_elem+0x546/0x6a0 kernel/bpf/lpm_trie.c:540 bpf_prog_7dc2717de7fcbdae+0x45/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 __traceiter_timer_start+0x75/0xc0 include/trace/events/timer.h:52 trace_timer_start include/trace/events/timer.h:52 [inline] enqueue_timer+0x3ce/0x570 kernel/time/timer.c:663 internal_add_timer kernel/time/timer.c:688 [inline] __mod_timer+0xa0e/0xeb0 kernel/time/timer.c:1183 queue_delayed_work_on+0x1ca/0x390 kernel/workqueue.c:2572 queue_delayed_work include/linux/workqueue.h:636 [inline] srcu_funnel_gp_start kernel/rcu/srcutree.c:1058 [inline] srcu_gp_start_if_needed+0xe65/0x11e0 kernel/rcu/srcutree.c:1302 tp_rcu_get_state kernel/tracepoint.c:53 [inline] tracepoint_remove_func kernel/tracepoint.c:426 [inline] tracepoint_probe_unregister+0x7c5/0x990 kernel/tracepoint.c:551 bpf_raw_tp_link_release+0x45/0x70 kernel/bpf/syscall.c:3541 bpf_link_free+0xf5/0x250 kernel/bpf/syscall.c:3067 bpf_link_put_direct kernel/bpf/syscall.c:3107 [inline] bpf_link_release+0x7b/0x90 kernel/bpf/syscall.c:3114 __fput+0x406/0x8b0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd08ac7cea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffead09ae28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000025217 RCX: 00007fd08ac7cea9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: ffffffffffffffff R08: 0000000000000001 R09: 0000000e00000000 R10: 00007fd08ac00000 R11: 0000000000000246 R12: 00007fd08adb3f80 R13: 00007fd08adb3f8c R14: 0000000000000032 R15: 00007fd08adb5980