====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.2585/15148 is trying to acquire lock: ffff8880b8f29370 (krc.lock){-.-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2959 [inline] ffff8880b8f29370 (krc.lock){-.-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3368 [inline] ffff8880b8f29370 (krc.lock){-.-.}-{2:2}, at: kvfree_call_rcu+0x166/0x790 kernel/rcu/tree.c:3453 but task is already holding lock: ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1754 [inline] ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5ef/0xc40 kernel/time/hrtimer.c:1814 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+0xb4/0x100 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:181 [inline] hrtimer_start_range_ns+0xf3/0xff0 kernel/time/hrtimer.c:1349 hrtimer_start include/linux/hrtimer.h:421 [inline] run_page_cache_worker kernel/rcu/tree.c:3350 [inline] kvfree_call_rcu+0x5e1/0x790 kernel/rcu/tree.c:3455 rtnl_register_internal+0x486/0x590 net/core/rtnetlink.c:264 rtnl_register+0x32/0x70 net/core/rtnetlink.c:314 ip_rt_init+0x2ec/0x390 net/ipv4/route.c:3801 ip_init+0xe/0x20 net/ipv4/ip_output.c:1668 inet_init+0x2c1/0x3e0 net/ipv4/af_inet.c:2024 do_one_initcall+0x242/0x790 init/main.c:1250 do_initcall_level+0x137/0x1f0 init/main.c:1312 do_initcalls+0x69/0xd0 init/main.c:1328 kernel_init_freeable+0x3ed/0x580 init/main.c:1565 kernel_init+0x1d/0x1c0 init/main.c:1455 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 -> #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 kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 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:2959 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3368 [inline] kvfree_call_rcu+0x166/0x790 kernel/rcu/tree.c:3453 trie_delete_elem+0x534/0x6a0 kernel/bpf/lpm_trie.c:545 bpf_prog_c0188993c79ab9c8+0x45/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:616 [inline] bpf_prog_run include/linux/filter.h:623 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d9/0x3e0 kernel/trace/bpf_trace.c:2361 __bpf_trace_hrtimer_start+0x123/0x170 include/trace/events/timer.h:202 __traceiter_hrtimer_start+0x6e/0xc0 include/trace/events/timer.h:202 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:506 [inline] enqueue_hrtimer+0x314/0x370 kernel/time/hrtimer.c:1108 __run_hrtimer kernel/time/hrtimer.c:1767 [inline] __hrtimer_run_queues+0x643/0xc40 kernel/time/hrtimer.c:1814 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 preempt_count arch/x86/include/asm/preempt.h:27 [inline] check_kcov_mode kernel/kcov.c:182 [inline] __sanitizer_cov_trace_pc+0x17/0x60 kernel/kcov.c:216 unwind_next_frame+0x853/0x2970 arch/x86/kernel/unwind_orc.c:517 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __set_page_owner+0x1d/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3191 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4457 vm_area_alloc_pages mm/vmalloc.c:3089 [inline] __vmalloc_area_node mm/vmalloc.c:3158 [inline] __vmalloc_node_range+0x956/0x1330 mm/vmalloc.c:3339 __bpf_map_area_alloc kernel/bpf/syscall.c:309 [inline] bpf_map_area_alloc+0xf1/0x110 kernel/bpf/syscall.c:316 dev_map_init_map kernel/bpf/devmap.c:148 [inline] dev_map_alloc+0x1f6/0x4c0 kernel/bpf/devmap.c:167 map_create+0x877/0x12f0 kernel/bpf/syscall.c:1247 __sys_bpf+0x651/0x890 kernel/bpf/syscall.c:5458 __do_sys_bpf kernel/bpf/syscall.c:5580 [inline] __se_sys_bpf kernel/bpf/syscall.c:5578 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5578 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 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 *** 2 locks held by syz.4.2585/15148: #0: ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1754 [inline] #0: ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5ef/0xc40 kernel/time/hrtimer.c:1814 #1: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #1: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #1: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xe6/0x3e0 kernel/trace/bpf_trace.c:2361 stack backtrace: CPU: 1 PID: 15148 Comm: syz.4.2585 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 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 kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 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:2959 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3368 [inline] kvfree_call_rcu+0x166/0x790 kernel/rcu/tree.c:3453 trie_delete_elem+0x534/0x6a0 kernel/bpf/lpm_trie.c:545 bpf_prog_c0188993c79ab9c8+0x45/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:616 [inline] bpf_prog_run include/linux/filter.h:623 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d9/0x3e0 kernel/trace/bpf_trace.c:2361 __bpf_trace_hrtimer_start+0x123/0x170 include/trace/events/timer.h:202 __traceiter_hrtimer_start+0x6e/0xc0 include/trace/events/timer.h:202 trace_hrtimer_start include/trace/events/timer.h:202 [inline] debug_activate kernel/time/hrtimer.c:506 [inline] enqueue_hrtimer+0x314/0x370 kernel/time/hrtimer.c:1108 __run_hrtimer kernel/time/hrtimer.c:1767 [inline] __hrtimer_run_queues+0x643/0xc40 kernel/time/hrtimer.c:1814 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x17/0x60 kernel/kcov.c:216 Code: 48 8b 3d fc c8 03 0d 48 89 de 5b e9 93 57 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 90 a2 7c 7e 65 8b 15 91 a2 7c 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 RSP: 0018:ffffc900032f7490 EFLAGS: 00000246 RAX: ffffffff813b3e73 RBX: ffffffff8f14a104 RCX: ffff888023e5da00 RDX: 0000000080000001 RSI: ffffffff8cfa0760 RDI: 0000000000000005 RBP: ffffc900032f75b8 R08: ffff888023e5da00 R09: 0000000000000008 R10: 0000000000000009 R11: 0000000000000002 R12: ffffc900032f7568 R13: dffffc0000000000 R14: 0000000000000005 R15: ffffffff8f14a108 unwind_next_frame+0x853/0x2970 arch/x86/kernel/unwind_orc.c:517 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __set_page_owner+0x1d/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3191 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4457 vm_area_alloc_pages mm/vmalloc.c:3089 [inline] __vmalloc_area_node mm/vmalloc.c:3158 [inline] __vmalloc_node_range+0x956/0x1330 mm/vmalloc.c:3339 __bpf_map_area_alloc kernel/bpf/syscall.c:309 [inline] bpf_map_area_alloc+0xf1/0x110 kernel/bpf/syscall.c:316 dev_map_init_map kernel/bpf/devmap.c:148 [inline] dev_map_alloc+0x1f6/0x4c0 kernel/bpf/devmap.c:167 map_create+0x877/0x12f0 kernel/bpf/syscall.c:1247 __sys_bpf+0x651/0x890 kernel/bpf/syscall.c:5458 __do_sys_bpf kernel/bpf/syscall.c:5580 [inline] __se_sys_bpf kernel/bpf/syscall.c:5578 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5578 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f713f99acb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f71408db028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f713fc15fa0 RCX: 00007f713f99acb9 RDX: 0000000000000050 RSI: 0000200000000bc0 RDI: 0000000000000000 RBP: 00007f713fa08bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f713fc16038 R14: 00007f713fc15fa0 R15: 00007ffc7f7b1ba8 ---------------- Code disassembly (best guess): 0: 48 8b 3d fc c8 03 0d mov 0xd03c8fc(%rip),%rdi # 0xd03c903 7: 48 89 de mov %rbx,%rsi a: 5b pop %rbx b: e9 93 57 57 00 jmp 0x5757a3 10: cc int3 11: cc int3 12: cc int3 13: f3 0f 1e fa endbr64 17: 48 8b 04 24 mov (%rsp),%rax 1b: 65 48 8b 0d 90 a2 7c mov %gs:0x7e7ca290(%rip),%rcx # 0x7e7ca2b3 22: 7e 23: 65 8b 15 91 a2 7c 7e mov %gs:0x7e7ca291(%rip),%edx # 0x7e7ca2bb * 2a: 81 e2 00 01 ff 00 and $0xff0100,%edx <-- trapping instruction 30: 74 11 je 0x43 32: 81 fa 00 01 00 00 cmp $0x100,%edx 38: 75 35 jne 0x6f 3a: 83 .byte 0x83 3b: b9 1c 16 00 00 mov $0x161c,%ecx