======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.9.6300/22393 is trying to acquire lock:
ffff8880b8f281d8 (krc.lock){-.-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2995 [inline]
ffff8880b8f281d8 (krc.lock){-.-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3315 [inline]
ffff8880b8f281d8 (krc.lock){-.-.}-{2:2}, at: kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3406

but task is already holding lock:
ffff8880b8f2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1751 [inline]
ffff8880b8f2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x63a/0xd60 kernel/time/hrtimer.c:1811

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:180 [inline]
       hrtimer_start_range_ns+0xec/0xfc0 kernel/time/hrtimer.c:1346
       hrtimer_start include/linux/hrtimer.h:421 [inline]
       run_page_cache_worker kernel/rcu/tree.c:3297 [inline]
       kvfree_call_rcu+0x6d0/0x870 kernel/rcu/tree.c:3408
       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:3796
       ip_init+0xa/0x14 net/ipv4/ip_output.c:1771
       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:2995 [inline]
       add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3315 [inline]
       kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3406
       trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545
       bpf_prog_5186c38a4019a4cb+0x42/0x46
       bpf_dispatcher_nop_func include/linux/bpf.h:1011 [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:2285 [inline]
       bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324
       trace_hrtimer_start include/trace/events/timer.h:202 [inline]
       debug_activate kernel/time/hrtimer.c:504 [inline]
       enqueue_hrtimer+0x36e/0x3f0 kernel/time/hrtimer.c:1105
       __run_hrtimer kernel/time/hrtimer.c:1764 [inline]
       __hrtimer_run_queues+0x68e/0xd60 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_kcov_mode kernel/kcov.c:184 [inline]
       write_comp_data kernel/kcov.c:245 [inline]
       __sanitizer_cov_trace_const_cmp8+0x32/0x80 kernel/kcov.c:320
       _compound_head include/linux/page-flags.h:255 [inline]
       PageAnon include/linux/page-flags.h:669 [inline]
       mm_counter include/linux/mm.h:2169 [inline]
       zap_pte_range mm/memory.c:1452 [inline]
       zap_pmd_range mm/memory.c:1574 [inline]
       zap_pud_range mm/memory.c:1603 [inline]
       zap_p4d_range mm/memory.c:1624 [inline]
       unmap_page_range+0x10c4/0x2500 mm/memory.c:1645
       unmap_vmas+0x22c/0x330 mm/memory.c:1730
       exit_mmap+0x1cc/0x8e0 mm/mmap.c:3250
       __mmput+0x118/0x3c0 kernel/fork.c:1200
       mmput kernel/fork.c:1222 [inline]
       dup_mm kernel/fork.c:1557 [inline]
       copy_mm+0x1312/0x15c0 kernel/fork.c:1590
       copy_process+0x1953/0x4020 kernel/fork.c:2351
       kernel_clone+0x225/0x8b0 kernel/fork.c:2757
       __do_sys_clone kernel/fork.c:2898 [inline]
       __se_sys_clone kernel/fork.c:2882 [inline]
       __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882
       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.9.6300/22393:
 #0: ffff8880743fe2d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
 #0: ffff8880743fe2d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x131/0x8e0 mm/mmap.c:3235
 #1: ffff888028e04cd8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #1: ffff888028e04cd8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pte_range mm/memory.c:1417 [inline]
 #1: ffff888028e04cd8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pmd_range mm/memory.c:1574 [inline]
 #1: ffff888028e04cd8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pud_range mm/memory.c:1603 [inline]
 #1: ffff888028e04cd8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_p4d_range mm/memory.c:1624 [inline]
 #1: ffff888028e04cd8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: unmap_page_range+0xa1b/0x2500 mm/memory.c:1645
 #2: ffff8880b8f2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1751 [inline]
 #2: ffff8880b8f2a598 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x63a/0xd60 kernel/time/hrtimer.c:1811
 #3: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #3: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #3: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 #3: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xda/0x3b0 kernel/trace/bpf_trace.c:2324

stack backtrace:
CPU: 1 PID: 22393 Comm: syz.9.6300 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <IRQ>
 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:2995 [inline]
 add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3315 [inline]
 kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3406
 trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545
 bpf_prog_5186c38a4019a4cb+0x42/0x46
 bpf_dispatcher_nop_func include/linux/bpf.h:1011 [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:2285 [inline]
 bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324
 trace_hrtimer_start include/trace/events/timer.h:202 [inline]
 debug_activate kernel/time/hrtimer.c:504 [inline]
 enqueue_hrtimer+0x36e/0x3f0 kernel/time/hrtimer.c:1105
 __run_hrtimer kernel/time/hrtimer.c:1764 [inline]
 __hrtimer_run_queues+0x68e/0xd60 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x32/0x80 kernel/kcov.c:320
Code: 64 9c 81 7e 65 8b 15 65 9c 81 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 1c 16 00 00 00 74 4e 8b 91 f8 15 00 00 <83> fa 03 75 43 48 8b 91 00 16 00 00 44 8b 89 fc 15 00 00 49 c1 e1
RSP: 0018:ffffc90003ae7398 EFLAGS: 00000246
RAX: ffffffff81bd1164 RBX: 0000000000000000 RCX: ffff88802ce13b80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003ae74f0 R08: dffffc0000000000 R09: fffffbfff1c3eee6
R10: fffffbfff1c3eee6 R11: 1ffffffff1c3eee5 R12: 1ffffd40002ed701
R13: ffffea000176b800 R14: ffffea000176b808 R15: 800000005dae0007
 _compound_head include/linux/page-flags.h:255 [inline]
 PageAnon include/linux/page-flags.h:669 [inline]
 mm_counter include/linux/mm.h:2169 [inline]
 zap_pte_range mm/memory.c:1452 [inline]
 zap_pmd_range mm/memory.c:1574 [inline]
 zap_pud_range mm/memory.c:1603 [inline]
 zap_p4d_range mm/memory.c:1624 [inline]
 unmap_page_range+0x10c4/0x2500 mm/memory.c:1645
 unmap_vmas+0x22c/0x330 mm/memory.c:1730
 exit_mmap+0x1cc/0x8e0 mm/mmap.c:3250
 __mmput+0x118/0x3c0 kernel/fork.c:1200
 mmput kernel/fork.c:1222 [inline]
 dup_mm kernel/fork.c:1557 [inline]
 copy_mm+0x1312/0x15c0 kernel/fork.c:1590
 copy_process+0x1953/0x4020 kernel/fork.c:2351
 kernel_clone+0x225/0x8b0 kernel/fork.c:2757
 __do_sys_clone kernel/fork.c:2898 [inline]
 __se_sys_clone kernel/fork.c:2882 [inline]
 __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882
 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: 0033:0x7f84b938eec9
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:00007f84ba22afe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f84b95e5fa0 RCX: 00007f84b938eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f84b9411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f84b95e6038 R14: 00007f84b95e5fa0 R15: 00007ffd8d9f4c78
 </TASK>
----------------
Code disassembly (best guess):
   0:	64 9c                	fs pushf
   2:	81 7e 65 8b 15 65 9c 	cmpl   $0x9c65158b,0x65(%rsi)
   9:	81 7e 81 e2 00 01 ff 	cmpl   $0xff0100e2,-0x7f(%rsi)
  10:	00 74 11 81          	add    %dh,-0x7f(%rcx,%rdx,1)
  14:	fa                   	cli
  15:	00 01                	add    %al,(%rcx)
  17:	00 00                	add    %al,(%rax)
  19:	75 57                	jne    0x72
  1b:	83 b9 1c 16 00 00 00 	cmpl   $0x0,0x161c(%rcx)
  22:	74 4e                	je     0x72
  24:	8b 91 f8 15 00 00    	mov    0x15f8(%rcx),%edx
* 2a:	83 fa 03             	cmp    $0x3,%edx <-- trapping instruction
  2d:	75 43                	jne    0x72
  2f:	48 8b 91 00 16 00 00 	mov    0x1600(%rcx),%rdx
  36:	44 8b 89 fc 15 00 00 	mov    0x15fc(%rcx),%r9d
  3d:	49                   	rex.WB
  3e:	c1                   	.byte 0xc1
  3f:	e1                   	.byte 0xe1