====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.10400/5711 is trying to acquire lock: ffff888077063238 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:467 but task is already holding lock: ffffffff96eda0c8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x68/0x4f0 lib/debugobjects.c:698 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&obj_hash[i].lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 __debug_check_no_obj_freed lib/debugobjects.c:968 [inline] debug_check_no_obj_freed+0x136/0x530 lib/debugobjects.c:1009 slab_free_hook mm/slub.c:1704 [inline] slab_free_freelist_hook+0xd2/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700 trie_update_elem+0x6bf/0xe80 kernel/bpf/lpm_trie.c:444 bpf_map_update_value+0x59e/0x670 kernel/bpf/syscall.c:228 generic_map_update_batch+0x54b/0x810 kernel/bpf/syscall.c:1709 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1 __sys_bpf+0x6f7/0x780 kernel/bpf/syscall.c:-1 __do_sys_bpf kernel/bpf/syscall.c:5134 [inline] __se_sys_bpf kernel/bpf/syscall.c:5132 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5132 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&trie->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+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:467 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:607 [inline] bpf_prog_run include/linux/filter.h:614 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1d5/0x3e0 kernel/trace/bpf_trace.c:2324 trace_contention_end+0x13f/0x190 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x7e8/0x9c0 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x265/0x2f0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xbc/0x100 kernel/locking/spinlock.c:162 debug_object_activate+0x68/0x4f0 lib/debugobjects.c:698 debug_hrtimer_activate kernel/time/hrtimer.c:448 [inline] debug_activate kernel/time/hrtimer.c:503 [inline] enqueue_hrtimer+0x30/0x3f0 kernel/time/hrtimer.c:1105 __run_hrtimer kernel/time/hrtimer.c:1764 [inline] __hrtimer_run_queues+0x69a/0xd70 kernel/time/hrtimer.c:1811 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 check_region_inline mm/kasan/generic.c:169 [inline] kasan_check_range+0xe/0x290 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:444 [inline] cpu_online include/linux/cpumask.h:1030 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0xc0/0x920 kernel/locking/lockdep.c:5673 up_read+0x12/0x20 kernel/locking/rwsem.c:1615 wireless_nlevent_flush net/wireless/wext-core.c:356 [inline] wext_netdev_notifier_call+0xf6/0x110 net/wireless/wext-core.c:370 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] register_netdevice+0x1640/0x1ae0 net/core/dev.c:10237 tun_set_iff+0x848/0xed0 drivers/net/tun.c:2851 __tun_chr_ioctl+0x781/0x1e60 drivers/net/tun.c:3114 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/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(&obj_hash[i].lock); lock(&trie->lock); lock(&obj_hash[i].lock); lock(&trie->lock); *** DEADLOCK *** 5 locks held by syz.1.10400/5711: #0: ffffffff8dd3e128 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3fc/0x1e60 drivers/net/tun.c:3104 #1: ffffffff8dd31410 (net_rwsem){++++}-{3:3}, at: wireless_nlevent_flush net/wireless/wext-core.c:350 [inline] #1: ffffffff8dd31410 (net_rwsem){++++}-{3:3}, at: wext_netdev_notifier_call+0x24/0x110 net/wireless/wext-core.c:370 #2: ffff8880b8f2a5d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1751 [inline] #2: ffff8880b8f2a5d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x646/0xd70 kernel/time/hrtimer.c:1811 #3: ffffffff96eda0c8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x68/0x4f0 lib/debugobjects.c:698 #4: ffffffff8cb2b2a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #4: ffffffff8cb2b2a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #4: ffffffff8cb2b2a0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] #4: ffffffff8cb2b2a0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xe2/0x3e0 kernel/trace/bpf_trace.c:2324 stack backtrace: CPU: 1 PID: 5711 Comm: syz.1.10400 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 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+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:467 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:607 [inline] bpf_prog_run include/linux/filter.h:614 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1d5/0x3e0 kernel/trace/bpf_trace.c:2324 trace_contention_end+0x13f/0x190 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x7e8/0x9c0 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x265/0x2f0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xbc/0x100 kernel/locking/spinlock.c:162 debug_object_activate+0x68/0x4f0 lib/debugobjects.c:698 debug_hrtimer_activate kernel/time/hrtimer.c:448 [inline] debug_activate kernel/time/hrtimer.c:503 [inline] enqueue_hrtimer+0x30/0x3f0 kernel/time/hrtimer.c:1105 __run_hrtimer kernel/time/hrtimer.c:1764 [inline] __hrtimer_run_queues+0x69a/0xd70 kernel/time/hrtimer.c:1811 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline] RIP: 0010:kasan_check_range+0xe/0x290 mm/kasan/generic.c:189 Code: 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 ac 01 00 00 55 41 57 <41> 56 41 54 53 49 89 f8 49 01 f0 0f 82 0e 02 00 00 49 89 f8 49 c1 RSP: 0018:ffffc90005ddf9c8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8164a340 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e1f4828 RBP: ffffc90005ddfb00 R08: ffffffff8e1f482f R09: 1ffffffff1c3e905 R10: dffffc0000000000 R11: fffffbfff1c3e906 R12: 1ffff92000bbbf48 R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff92000bbbf48 instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:444 [inline] cpu_online include/linux/cpumask.h:1030 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0xc0/0x920 kernel/locking/lockdep.c:5673 up_read+0x12/0x20 kernel/locking/rwsem.c:1615 wireless_nlevent_flush net/wireless/wext-core.c:356 [inline] wext_netdev_notifier_call+0xf6/0x110 net/wireless/wext-core.c:370 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] register_netdevice+0x1640/0x1ae0 net/core/dev.c:10237 tun_set_iff+0x848/0xed0 drivers/net/tun.c:2851 __tun_chr_ioctl+0x781/0x1e60 drivers/net/tun.c:3114 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8cf2b9acb9 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:00007f8cf3ace028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8cf2e16090 RCX: 00007f8cf2b9acb9 RDX: 00002000000000c0 RSI: 00000000400454ca RDI: 000000000000000b RBP: 00007f8cf2c08bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8cf2e16128 R14: 00007f8cf2e16090 R15: 00007ffd8fcf8ac8 ---------------- Code disassembly (best guess): 0: 0f 0b ud2 2: b8 ea ff ff ff mov $0xffffffea,%eax 7: c3 ret 8: 0f 0b ud2 a: b8 ea ff ff ff mov $0xffffffea,%eax f: c3 ret 10: 00 00 add %al,(%rax) 12: cc int3 13: cc int3 14: 00 00 add %al,(%rax) 16: cc int3 17: cc int3 18: 00 00 add %al,(%rax) 1a: cc int3 1b: cc int3 1c: b0 01 mov $0x1,%al 1e: 48 85 f6 test %rsi,%rsi 21: 0f 84 ac 01 00 00 je 0x1d3 27: 55 push %rbp 28: 41 57 push %r15 * 2a: 41 56 push %r14 <-- trapping instruction 2c: 41 54 push %r12 2e: 53 push %rbx 2f: 49 89 f8 mov %rdi,%r8 32: 49 01 f0 add %rsi,%r8 35: 0f 82 0e 02 00 00 jb 0x249 3b: 49 89 f8 mov %rdi,%r8 3e: 49 rex.WB 3f: c1 .byte 0xc1