======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.1423/8013 is trying to acquire lock:
ffff8880b9127eb8 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3203 [inline]
ffff8880b9127eb8 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3510 [inline]
ffff8880b9127eb8 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x186/0x7c0 kernel/rcu/tree.c:3601

but task is already holding lock:
ffff88801f06d238 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&trie->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
       trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467
       0xffffffffa0018b02
       bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
       bpf_trace_run2+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915
       trace_hrtimer_start include/trace/events/timer.h:199 [inline]
       debug_activate kernel/time/hrtimer.c:466 [inline]
       enqueue_hrtimer+0x314/0x370 kernel/time/hrtimer.c:1069
       __hrtimer_start_range_ns kernel/time/hrtimer.c:1244 [inline]
       hrtimer_start_range_ns+0xa7e/0xc20 kernel/time/hrtimer.c:1286
       futex_wait_queue_me+0x18c/0x440 kernel/futex/core.c:2850
       futex_wait+0x202/0x5c0 kernel/futex/core.c:2964
       do_futex+0xd1c/0x1240 kernel/futex/core.c:3982
       __do_sys_futex kernel/futex/core.c:4059 [inline]
       __se_sys_futex+0x3a3/0x430 kernel/futex/core.c:4040
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #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:168 [inline]
       hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1284
       hrtimer_start include/linux/hrtimer.h:420 [inline]
       run_page_cache_worker kernel/rcu/tree.c:3492 [inline]
       kvfree_call_rcu+0x60d/0x7c0 kernel/rcu/tree.c:3603
       rtnl_register_internal+0x489/0x590 net/core/rtnetlink.c:225
       rtnl_register+0x2e/0x70 net/core/rtnetlink.c:275
       ip_rt_init+0x2e0/0x3a0 net/ipv4/route.c:3798
       ip_init+0xa/0x20 net/ipv4/ip_output.c:1749
       inet_init+0x28b/0x3a0 net/ipv4/af_inet.c:2007
       do_one_initcall+0x1ee/0x680 init/main.c:1316
       do_initcall_level+0x137/0x1f0 init/main.c:1389
       do_initcalls+0x4b/0x90 init/main.c:1405
       kernel_init_freeable+0x3ce/0x560 init/main.c:1629
       kernel_init+0x19/0x1b0 init/main.c:1520
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

-> #0 (krc.lock){..-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
       krc_this_cpu_lock kernel/rcu/tree.c:3203 [inline]
       add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3510 [inline]
       kvfree_call_rcu+0x186/0x7c0 kernel/rcu/tree.c:3601
       trie_delete_elem+0x58c/0x710 kernel/bpf/lpm_trie.c:-1
       bpf_prog_8c8ab8634bca3061+0x3a/0x940
       bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
       bpf_trace_run3+0x17e/0x320 kernel/trace/bpf_trace.c:1916
       __bpf_trace_kmem_cache_free+0x99/0xc0 include/trace/events/kmem.h:138
       trace_kmem_cache_free include/trace/events/kmem.h:138 [inline]
       kmem_cache_free+0x1e7/0x210 mm/slub.c:3521
       packet_rcv+0x16a/0x1210 net/packet/af_packet.c:2243
       dev_queue_xmit_nit+0xa69/0xb00 net/core/dev.c:2373
       xmit_one net/core/dev.c:3644 [inline]
       dev_hard_start_xmit+0x13e/0x7e0 net/core/dev.c:3665
       sch_direct_xmit+0x24e/0x4a0 net/sched/sch_generic.c:342
       __dev_xmit_skb net/core/dev.c:3884 [inline]
       __dev_queue_xmit+0x170e/0x2ed0 net/core/dev.c:4253
       neigh_hh_output include/net/neighbour.h:493 [inline]
       neigh_output include/net/neighbour.h:507 [inline]
       ip_finish_output2+0xc69/0x1080 net/ipv4/ip_output.c:228
       dst_output include/net/dst.h:452 [inline]
       ip_local_out net/ipv4/ip_output.c:126 [inline]
       __ip_queue_xmit+0x11c3/0x1c00 net/ipv4/ip_output.c:532
       __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404
       tcp_delack_timer_handler+0x32e/0x730 net/ipv4/tcp_timer.c:314
       tcp_delack_timer+0x188/0x2e0 net/ipv4/tcp_timer.c:341
       call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
       expire_timers kernel/time/timer.c:1496 [inline]
       __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
       run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
       handle_softirqs+0x328/0x820 kernel/softirq.c:576
       __do_softirq kernel/softirq.c:610 [inline]
       invoke_softirq kernel/softirq.c:450 [inline]
       __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
       irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
       instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
       sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
       core_kernel_text kernel/extable.c:104 [inline]
       kernel_text_address kernel/extable.c:125 [inline]
       __kernel_text_address+0x3/0x100 kernel/extable.c:105
       unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
       arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
       stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
       save_stack+0xf3/0x1e0 mm/page_owner.c:119
       __set_page_owner+0x41/0x2d0 mm/page_owner.c:181
       prep_new_page mm/page_alloc.c:2426 [inline]
       get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
       __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
       alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
       shmem_alloc_page mm/shmem.c:1586 [inline]
       shmem_alloc_and_acct_page+0x427/0xb70 mm/shmem.c:1611
       shmem_getpage_gfp+0x14f4/0x2d40 mm/shmem.c:1906
       shmem_fault+0x1a9/0x520 mm/shmem.c:2118
       __do_fault+0x141/0x330 mm/memory.c:3928
       do_read_fault mm/memory.c:4264 [inline]
       do_fault mm/memory.c:4392 [inline]
       handle_pte_fault mm/memory.c:4650 [inline]
       __handle_mm_fault mm/memory.c:4785 [inline]
       handle_mm_fault+0x2946/0x43b0 mm/memory.c:4883
       faultin_page mm/gup.c:976 [inline]
       __get_user_pages+0x93e/0x11c0 mm/gup.c:1197
       populate_vma_page_range+0x213/0x290 mm/gup.c:1529
       __mm_populate+0x26f/0x3a0 mm/gup.c:1638
       mm_populate include/linux/mm.h:2646 [inline]
       vm_mmap_pgoff+0x203/0x2b0 mm/util.c:556
       ksys_mmap_pgoff+0x140/0x780 mm/mmap.c:1635
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
  krc.lock --> hrtimer_bases.lock --> &trie->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&trie->lock);
                               lock(hrtimer_bases.lock);
                               lock(&trie->lock);
  lock(krc.lock);

 *** DEADLOCK ***

11 locks held by syz.4.1423/8013:
 #0: ffff88802c1a7828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
 #0: ffff88802c1a7828 (&mm->mmap_lock){++++}-{3:3}, at: __mm_populate+0x15e/0x3a0 mm/gup.c:1618
 #1: ffffc90000dd0be0 ((&icsk->icsk_delack_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline]
 #1: ffffc90000dd0be0 ((&icsk->icsk_delack_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbb/0x530 kernel/time/timer.c:1441
 #2: ffff888029f118a0 (slock-AF_INET){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
 #2: ffff888029f118a0 (slock-AF_INET){+.-.}-{2:2}, at: tcp_delack_timer+0x2b/0x2e0 net/ipv4/tcp_timer.c:339
 #3: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:313
 #4: ffffffff8c11c7c0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:313
 #5: ffffffff8c11c7c0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:313
 #6: ffff888023371258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:374 [inline]
 #6: ffff888023371258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:173 [inline]
 #6: ffff888023371258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3871 [inline]
 #6: ffff888023371258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x10b9/0x2ed0 net/core/dev.c:4253
 #7: ffff888022618218 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
 #7: ffff888022618218 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4446 [inline]
 #7: ffff888022618218 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x156/0x4a0 net/sched/sch_generic.c:340
 #8: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:313
 #9: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312
 #10: ffff88801f06d238 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467

stack backtrace:
CPU: 1 PID: 8013 Comm: syz.4.1423 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 krc_this_cpu_lock kernel/rcu/tree.c:3203 [inline]
 add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3510 [inline]
 kvfree_call_rcu+0x186/0x7c0 kernel/rcu/tree.c:3601
 trie_delete_elem+0x58c/0x710 kernel/bpf/lpm_trie.c:-1
 bpf_prog_8c8ab8634bca3061+0x3a/0x940
 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
 bpf_trace_run3+0x17e/0x320 kernel/trace/bpf_trace.c:1916
 __bpf_trace_kmem_cache_free+0x99/0xc0 include/trace/events/kmem.h:138
 trace_kmem_cache_free include/trace/events/kmem.h:138 [inline]
 kmem_cache_free+0x1e7/0x210 mm/slub.c:3521
 packet_rcv+0x16a/0x1210 net/packet/af_packet.c:2243
 dev_queue_xmit_nit+0xa69/0xb00 net/core/dev.c:2373
 xmit_one net/core/dev.c:3644 [inline]
 dev_hard_start_xmit+0x13e/0x7e0 net/core/dev.c:3665
 sch_direct_xmit+0x24e/0x4a0 net/sched/sch_generic.c:342
 __dev_xmit_skb net/core/dev.c:3884 [inline]
 __dev_queue_xmit+0x170e/0x2ed0 net/core/dev.c:4253
 neigh_hh_output include/net/neighbour.h:493 [inline]
 neigh_output include/net/neighbour.h:507 [inline]
 ip_finish_output2+0xc69/0x1080 net/ipv4/ip_output.c:228
 dst_output include/net/dst.h:452 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 __ip_queue_xmit+0x11c3/0x1c00 net/ipv4/ip_output.c:532
 __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404
 tcp_delack_timer_handler+0x32e/0x730 net/ipv4/tcp_timer.c:314
 tcp_delack_timer+0x188/0x2e0 net/ipv4/tcp_timer.c:341
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:core_kernel_text kernel/extable.c:104 [inline]
RIP: 0010:kernel_text_address kernel/extable.c:125 [inline]
RIP: 0010:__kernel_text_address+0x3/0x100 kernel/extable.c:105
Code: b1 66 0f 1f 44 00 00 48 81 ff 00 00 e0 8b 0f 93 c0 48 81 ff 40 a7 6b 8d 0f 92 c1 20 c1 0f b6 c1 c3 66 0f 1f 44 00 00 55 41 57 <41> 56 53 48 81 ff 00 00 00 81 0f 93 c0 48 81 ff c3 7d e0 89 0f 92
RSP: 0018:ffffc900033bec50 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900033becd0 RCX: 0000000080000000
RDX: ffffc900033bec01 RSI: ffffc900033bfe30 RDI: ffffffff81ae2900
RBP: ffffc900033bed10 R08: dffffc0000000000 R09: ffffc900033becd8
R10: fffff52000677d9d R11: 1ffff92000677d9b R12: ffff888025870000
R13: 1ffff92000677dbc R14: dffffc0000000000 R15: 1ffff92000677d9a
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 save_stack+0xf3/0x1e0 mm/page_owner.c:119
 __set_page_owner+0x41/0x2d0 mm/page_owner.c:181
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
 shmem_alloc_page mm/shmem.c:1586 [inline]
 shmem_alloc_and_acct_page+0x427/0xb70 mm/shmem.c:1611
 shmem_getpage_gfp+0x14f4/0x2d40 mm/shmem.c:1906
 shmem_fault+0x1a9/0x520 mm/shmem.c:2118
 __do_fault+0x141/0x330 mm/memory.c:3928
 do_read_fault mm/memory.c:4264 [inline]
 do_fault mm/memory.c:4392 [inline]
 handle_pte_fault mm/memory.c:4650 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x2946/0x43b0 mm/memory.c:4883
 faultin_page mm/gup.c:976 [inline]
 __get_user_pages+0x93e/0x11c0 mm/gup.c:1197
 populate_vma_page_range+0x213/0x290 mm/gup.c:1529
 __mm_populate+0x26f/0x3a0 mm/gup.c:1638
 mm_populate include/linux/mm.h:2646 [inline]
 vm_mmap_pgoff+0x203/0x2b0 mm/util.c:556
 ksys_mmap_pgoff+0x140/0x780 mm/mmap.c:1635
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1b992eb6c9
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:00007f1b97552038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f1b99541fa0 RCX: 00007f1b992eb6c9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f1b9936df91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1b99542038 R14: 00007f1b99541fa0 R15: 00007ffeab091f28
 </TASK>
----------------
Code disassembly (best guess):
   0:	b1 66                	mov    $0x66,%cl
   2:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   7:	48 81 ff 00 00 e0 8b 	cmp    $0xffffffff8be00000,%rdi
   e:	0f 93 c0             	setae  %al
  11:	48 81 ff 40 a7 6b 8d 	cmp    $0xffffffff8d6ba740,%rdi
  18:	0f 92 c1             	setb   %cl
  1b:	20 c1                	and    %al,%cl
  1d:	0f b6 c1             	movzbl %cl,%eax
  20:	c3                   	ret
  21:	66 0f 1f 44 00 00    	nopw   0x0(%rax,%rax,1)
  27:	55                   	push   %rbp
  28:	41 57                	push   %r15
* 2a:	41 56                	push   %r14 <-- trapping instruction
  2c:	53                   	push   %rbx
  2d:	48 81 ff 00 00 00 81 	cmp    $0xffffffff81000000,%rdi
  34:	0f 93 c0             	setae  %al
  37:	48 81 ff c3 7d e0 89 	cmp    $0xffffffff89e07dc3,%rdi
  3e:	0f                   	.byte 0xf
  3f:	92                   	xchg   %eax,%edx