====================================================== WARNING: possible circular locking dependency detected 6.6.94-syzkaller #0 Not tainted ------------------------------------------------------ syz.7.274/7118 is trying to acquire lock: ffff8880b8f295a8 (krc.lock){-.-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2955 [inline] ffff8880b8f295a8 (krc.lock){-.-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3364 [inline] ffff8880b8f295a8 (krc.lock){-.-.}-{2:2}, at: kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3449 but task is already holding lock: ffff8880b8f2b958 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1759 [inline] ffff8880b8f2b958 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5e3/0xc40 kernel/time/hrtimer.c:1819 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+0xa8/0xf0 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:181 [inline] hrtimer_start_range_ns+0xf3/0x1000 kernel/time/hrtimer.c:1354 hrtimer_start include/linux/hrtimer.h:421 [inline] run_page_cache_worker kernel/rcu/tree.c:3346 [inline] kvfree_call_rcu+0x5d5/0x780 kernel/rcu/tree.c:3451 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:3789 ip_init+0xe/0x20 net/ipv4/ip_output.c:1663 inet_init+0x2c1/0x3e0 net/ipv4/af_inet.c:2024 do_one_initcall+0x1fd/0x750 init/main.c:1238 do_initcall_level+0x137/0x1f0 init/main.c:1300 do_initcalls+0x69/0xd0 init/main.c:1316 kernel_init_freeable+0x3d2/0x570 init/main.c:1553 kernel_init+0x1d/0x1c0 init/main.c:1443 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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 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:2955 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3364 [inline] kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3449 trie_delete_elem+0x535/0x6a0 kernel/bpf/lpm_trie.c:545 bpf_prog_5186c38a4019a4cb+0x4a/0x4e bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361 __bpf_trace_hrtimer_start+0xfb/0x150 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+0x318/0x370 kernel/time/hrtimer.c:1113 __run_hrtimer kernel/time/hrtimer.c:1772 [inline] __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1819 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881 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+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194 debug_rcu_head_unqueue kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2186 [inline] rcu_core+0xc3b/0x1720 kernel/rcu/tree.c:2467 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 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+0x130/0x2970 arch/x86/kernel/unwind_orc.c:482 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509 kmem_cache_zalloc include/linux/slab.h:711 [inline] lsm_inode_alloc security/security.c:633 [inline] security_inode_alloc+0x34/0x110 security/security.c:1494 inode_init_always+0x8fc/0xc90 fs/inode.c:232 alloc_inode fs/inode.c:268 [inline] new_inode_pseudo+0x95/0x1d0 fs/inode.c:1049 sock_alloc net/socket.c:634 [inline] __sock_create+0x12d/0x940 net/socket.c:1535 inet_ctl_sock_create+0x9b/0x220 net/ipv4/af_inet.c:1688 igmp6_net_init+0x18e/0x3f0 net/ipv6/mcast.c:3148 ops_init+0x397/0x640 net/core/net_namespace.c:139 setup_net+0x3a5/0xa00 net/core/net_namespace.c:343 copy_net_ns+0x36d/0x5e0 net/core/net_namespace.c:520 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 copy_namespaces+0x430/0x4a0 kernel/nsproxy.c:179 copy_process+0x1700/0x3d70 kernel/fork.c:2509 kernel_clone+0x21b/0x840 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x18c/0x1e0 kernel/fork.c:3041 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 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 *** 3 locks held by syz.7.274/7118: #0: ffffffff8dfa1ed0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516 #1: ffff8880b8f2b958 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1759 [inline] #1: ffff8880b8f2b958 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5e3/0xc40 kernel/time/hrtimer.c:1819 #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #2: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361 stack backtrace: CPU: 1 PID: 7118 Comm: syz.7.274 Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 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:2955 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3364 [inline] kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3449 trie_delete_elem+0x535/0x6a0 kernel/bpf/lpm_trie.c:545 bpf_prog_5186c38a4019a4cb+0x4a/0x4e bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361 __bpf_trace_hrtimer_start+0xfb/0x150 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+0x318/0x370 kernel/time/hrtimer.c:1113 __run_hrtimer kernel/time/hrtimer.c:1772 [inline] __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1819 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881 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+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 7a 26 1c f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 82 91 eb f6 65 8b 05 93 e7 93 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900001f0b40 EFLAGS: 00000206 RAX: eb11de1d965f2200 RBX: 0000000000000a06 RCX: eb11de1d965f2200 RDX: dffffc0000000000 RSI: ffffffff8aaab2c0 RDI: 0000000000000001 RBP: ffffc900001f0bd0 R08: ffffffff90d8552f R09: 1ffffffff21b0aa5 R10: dffffc0000000000 R11: fffffbfff21b0aa6 R12: dffffc0000000000 R13: ffffffff81712d01 R14: ffffffff9713c000 R15: 1ffff9200003e168 debug_rcu_head_unqueue kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2186 [inline] rcu_core+0xc3b/0x1720 kernel/rcu/tree.c:2467 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 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 8c 17 c4 0c 48 89 de 5b e9 83 d6 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 20 24 7e 7e 65 8b 15 21 24 7e 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:ffffc900036bf030 EFLAGS: 00000246 RAX: ffffffff813a93f0 RBX: 1ffff920006d7e21 RCX: ffff888031360000 RDX: 0000000080000001 RSI: 0000000000000001 RDI: ffffffff813a937e RBP: ffffc900036bf158 R08: ffffc900036bf1d0 R09: 000000000000000d R10: 0000000000000004 R11: 0000000000000002 R12: ffffc900036bf108 R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff81595aa3 unwind_next_frame+0x130/0x2970 arch/x86/kernel/unwind_orc.c:482 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509 kmem_cache_zalloc include/linux/slab.h:711 [inline] lsm_inode_alloc security/security.c:633 [inline] security_inode_alloc+0x34/0x110 security/security.c:1494 inode_init_always+0x8fc/0xc90 fs/inode.c:232 alloc_inode fs/inode.c:268 [inline] new_inode_pseudo+0x95/0x1d0 fs/inode.c:1049 sock_alloc net/socket.c:634 [inline] __sock_create+0x12d/0x940 net/socket.c:1535 inet_ctl_sock_create+0x9b/0x220 net/ipv4/af_inet.c:1688 igmp6_net_init+0x18e/0x3f0 net/ipv6/mcast.c:3148 ops_init+0x397/0x640 net/core/net_namespace.c:139 setup_net+0x3a5/0xa00 net/core/net_namespace.c:343 copy_net_ns+0x36d/0x5e0 net/core/net_namespace.c:520 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 copy_namespaces+0x430/0x4a0 kernel/nsproxy.c:179 copy_process+0x1700/0x3d70 kernel/fork.c:2509 kernel_clone+0x21b/0x840 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x18c/0x1e0 kernel/fork.c:3041 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1c8738e929 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:00007f1c882abfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f1c875b5fa0 RCX: 00007f1c8738e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000042164000 RBP: 00007f1c87410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1c875b5fa0 R15: 00007ffe689dc7b8 ---------------- Code disassembly (best guess): 0: 74 05 je 0x7 2: e8 7a 26 1c f7 call 0xf71c2681 7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp) e: 00 00 10: 9c pushf 11: 8f 44 24 20 pop 0x20(%rsp) 15: f6 44 24 21 02 testb $0x2,0x21(%rsp) 1a: 75 4b jne 0x67 1c: f7 c3 00 02 00 00 test $0x200,%ebx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 82 91 eb f6 call 0xf6eb91b1 <-- trapping instruction 2f: 65 8b 05 93 e7 93 75 mov %gs:0x7593e793(%rip),%eax # 0x7593e7c9 36: 85 c0 test %eax,%eax 38: 74 3c je 0x76 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss