====================================================== WARNING: possible circular locking dependency detected 6.1.135-syzkaller #0 Not tainted ------------------------------------------------------ syz.2.578/5808 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: lock_hrtimer_base kernel/time/hrtimer.c:169 [inline] ffff8880b8e2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1290 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:169 [inline] hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1290 hrtimer_start include/linux/hrtimer.h:420 [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:3789 ip_init+0xa/0x14 net/ipv4/ip_output.c:1770 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_d46ba5bef82912c0+0x3d/0x41 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:2284 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2323 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:467 [inline] enqueue_hrtimer+0x36e/0x3f0 kernel/time/hrtimer.c:1075 __hrtimer_start_range_ns kernel/time/hrtimer.c:1250 [inline] hrtimer_start_range_ns+0xa7e/0xc20 kernel/time/hrtimer.c:1292 cpu_clock_event_add+0x32/0x40 kernel/events/core.c:10978 event_sched_in+0x6a1/0xe20 kernel/events/core.c:2575 group_sched_in kernel/events/core.c:2611 [inline] merge_sched_in+0x25f/0x1130 kernel/events/core.c:3803 visit_groups_merge+0xb58/0x1400 kernel/events/core.c:3747 ctx_flexible_sched_in+0x52/0x80 kernel/events/core.c:3845 perf_event_sched_in kernel/events/core.c:-1 [inline] perf_event_context_sched_in+0x334/0x5d0 kernel/events/core.c:3942 __perf_event_task_sched_in+0xcd/0x1d0 kernel/events/core.c:3975 perf_event_task_sched_in include/linux/perf_event.h:1283 [inline] finish_task_switch+0x60c/0x8f0 kernel/sched/core.c:5118 context_switch kernel/sched/core.c:5247 [inline] __schedule+0x10f1/0x40d0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 lock_release+0x593/0x910 kernel/locking/lockdep.c:5686 _copy_from_user+0x27/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:161 [inline] generic_map_update_batch+0x518/0x850 kernel/bpf/syscall.c:1699 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1 __sys_bpf+0x65f/0x6d0 kernel/bpf/syscall.c:-1 __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 *** 4 locks held by syz.2.578/5808: #0: ffff8880b8e40ae0 (&cpuctx_lock){-.-.}-{2:2}, at: perf_ctx_lock kernel/events/core.c:167 [inline] #0: ffff8880b8e40ae0 (&cpuctx_lock){-.-.}-{2:2}, at: perf_event_context_sched_in+0x105/0x5d0 kernel/events/core.c:3923 #1: ffff888059a8d820 (&ctx->lock){-.-.}-{2:2}, at: perf_ctx_lock kernel/events/core.c:169 [inline] #1: ffff888059a8d820 (&ctx->lock){-.-.}-{2:2}, at: perf_event_context_sched_in+0x11c/0x5d0 kernel/events/core.c:3923 #2: ffff8880b8e2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: lock_hrtimer_base kernel/time/hrtimer.c:169 [inline] #2: ffff8880b8e2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1290 #3: ffffffff8c92a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #3: ffffffff8c92a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #3: ffffffff8c92a9e0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline] #3: ffffffff8c92a9e0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xda/0x3b0 kernel/trace/bpf_trace.c:2323 stack backtrace: CPU: 0 PID: 5808 Comm: syz.2.578 Not tainted 6.1.135-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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_d46ba5bef82912c0+0x3d/0x41 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:2284 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2323 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:467 [inline] enqueue_hrtimer+0x36e/0x3f0 kernel/time/hrtimer.c:1075 __hrtimer_start_range_ns kernel/time/hrtimer.c:1250 [inline] hrtimer_start_range_ns+0xa7e/0xc20 kernel/time/hrtimer.c:1292 cpu_clock_event_add+0x32/0x40 kernel/events/core.c:10978 event_sched_in+0x6a1/0xe20 kernel/events/core.c:2575 group_sched_in kernel/events/core.c:2611 [inline] merge_sched_in+0x25f/0x1130 kernel/events/core.c:3803 visit_groups_merge+0xb58/0x1400 kernel/events/core.c:3747 ctx_flexible_sched_in+0x52/0x80 kernel/events/core.c:3845 perf_event_sched_in kernel/events/core.c:-1 [inline] perf_event_context_sched_in+0x334/0x5d0 kernel/events/core.c:3942 __perf_event_task_sched_in+0xcd/0x1d0 kernel/events/core.c:3975 perf_event_task_sched_in include/linux/perf_event.h:1283 [inline] finish_task_switch+0x60c/0x8f0 kernel/sched/core.c:5118 context_switch kernel/sched/core.c:5247 [inline] __schedule+0x10f1/0x40d0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_release+0x593/0x910 kernel/locking/lockdep.c:5686 Code: 00 00 00 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 75 75 f7 44 24 50 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 66 43 c7 44 2f 09 00 00 43 c6 44 2f 0b 00 RSP: 0018:ffffc900043e7a80 EFLAGS: 00000206 RAX: 0000000000000001 RBX: ffffffffffffffff RCX: 1a58b404e6da2900 RDX: 0000000000000000 RSI: ffffffff8a6c1080 RDI: ffffffff8abf0ea0 RBP: ffffc900043e7ba0 R08: dffffc0000000000 R09: fffffbfff1bfcf4e R10: fffffbfff1bfcf4e R11: 1ffffffff1bfcf4d R12: ffff88802474a8a0 R13: dffffc0000000000 R14: ffff88802474a890 R15: 1ffff9200087cf5c _copy_from_user+0x27/0x170 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:161 [inline] generic_map_update_batch+0x518/0x850 kernel/bpf/syscall.c:1699 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1 __sys_bpf+0x65f/0x6d0 kernel/bpf/syscall.c:-1 __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: 0033:0x7f5b2538e969 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:00007f5b261cd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f5b255b5fa0 RCX: 00007f5b2538e969 RDX: 0000000000000038 RSI: 00002000000002c0 RDI: 000000000000001a RBP: 00007f5b25410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5b255b5fa0 R15: 00007fffd001c0d8 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 9c pushf 5: 8f 84 24 80 00 00 00 pop 0x80(%rsp) c: f6 84 24 81 00 00 00 testb $0x2,0x81(%rsp) 13: 02 14: 75 75 jne 0x8b 16: f7 44 24 50 00 02 00 testl $0x200,0x50(%rsp) 1d: 00 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp) 28: e0 45 * 2a: 4b c7 04 2f 00 00 00 movq $0x0,(%r15,%r13,1) <-- trapping instruction 31: 00 32: 66 43 c7 44 2f 09 00 movw $0x0,0x9(%r15,%r13,1) 39: 00 3a: 43 c6 44 2f 0b 00 movb $0x0,0xb(%r15,%r13,1)