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WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049, CPU#1: udevd/31422
Modules linked in:
CPU: 1 UID: 0 PID: 31422 Comm: udevd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049
Code: ff ff 48 c7 c7 a0 85 8f 99 be 04 00 00 00 e8 03 90 7f 00 4c 89 f7 b8 01 00 00 00 87 05 25 f8 e7 17 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 80 6e f4 8d 74 47 48 c7 c0 a0 54 82 8f 48 c1 e8
RSP: 0000:ffffc90000a08d98 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff81a78d6d
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8df46e80
RBP: ffffc90000a08f30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff331f0b4 R12: 0000000000002904
R13: 1ffff110170e771a R14: ffffffff8df46e80 R15: dffffc0000000000
FS:  00007fd379f98880(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b72cdbdf28 CR3: 00000000213ca000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_core+0x5f5/0x1720 kernel/rcu/tree.c:2852
 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x60/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8f 93 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 73 93
RSP: 0000:ffffc90004b5f820 EFLAGS: 00000293
RAX: ffffffff81b564dd RBX: 1ffff110170c856d RCX: ffff88807f68bd00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004b5f950 R08: ffffffff8f822477 R09: 1ffffffff1f0448e
R10: dffffc0000000000 R11: fffffbfff1f0448f R12: ffff8880b8642b68
R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
 flush_tlb_mm_range+0x60a/0x1170 arch/x86/mm/tlb.c:1472
 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
 ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:103
 wp_page_copy mm/memory.c:3785 [inline]
 do_wp_page+0x1bb1/0x5810 mm/memory.c:4180
 handle_pte_fault mm/memory.c:6289 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6580
 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fd3798b5b69
Code: 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 48 85 d2 74 1f 48 3b 7a 28 75 76 48 8b 4f 28 48 3b 79 20 75 6c 48 83 78 20 00 74 17 <48> 89 4a 28 48 89 51 20 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd8fd3aa50 EFLAGS: 00010202
RAX: 00007fd3799f2290 RBX: 000000000000aac0 RCX: 000055b72cdbdf00
RDX: 000055b72cdbdf00 RSI: 00007fd3799f2290 RDI: 000055b72cdbdf00
RBP: 00007fd3799f1ac0 R08: 000000000000aac0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055b72cdbb7a0
R13: 00007fd3799f1ac0 R14: 000000000000aac0 R15: 00007fd3799f1ac0
 </TASK>
----------------
Code disassembly (best guess):
   0:	45 8b 2c 24          	mov    (%r12),%r13d
   4:	44 89 ee             	mov    %r13d,%esi
   7:	83 e6 01             	and    $0x1,%esi
   a:	31 ff                	xor    %edi,%edi
   c:	e8 e4 97 0b 00       	call   0xb97f5
  11:	41 83 e5 01          	and    $0x1,%r13d
  15:	49 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%r13
  1c:	fc ff df
  1f:	75 07                	jne    0x28
  21:	e8 8f 93 0b 00       	call   0xb93b5
  26:	eb 38                	jmp    0x60
  28:	f3 90                	pause
* 2a:	42 0f b6 04 2b       	movzbl (%rbx,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	75 11                	jne    0x44
  33:	41 f7 04 24 01 00 00 	testl  $0x1,(%r12)
  3a:	00
  3b:	74 1e                	je     0x5b
  3d:	e8                   	.byte 0xe8
  3e:	73 93                	jae    0xffffffd3