------------[ cut here ]------------
WARNING: ./include/linux/ns_common.h:255 at __ns_ref_put include/linux/ns_common.h:255 [inline], CPU#0: syz.3.65/6139
WARNING: ./include/linux/ns_common.h:255 at put_user_ns include/linux/user_namespace.h:189 [inline], CPU#0: syz.3.65/6139
WARNING: ./include/linux/ns_common.h:255 at put_cred_rcu+0x2c5/0x340 kernel/cred.c:61, CPU#0: syz.3.65/6139
Modules linked in:
CPU: 0 UID: 0 PID: 6139 Comm: syz.3.65 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__ns_ref_put include/linux/ns_common.h:255 [inline]
RIP: 0010:put_user_ns include/linux/user_namespace.h:189 [inline]
RIP: 0010:put_cred_rcu+0x2c5/0x340 kernel/cred.c:61
Code: 5c 41 5d 41 5e 41 5f 5d e9 b8 25 8e 00 e8 13 a7 32 00 4c 89 e7 be 03 00 00 00 e8 a6 02 02 03 e9 b8 fe ff ff e8 fc a6 32 00 90 <0f> 0b 90 eb 9f e8 f1 a6 32 00 4c 89 ff be 03 00 00 00 e8 84 02 02
RSP: 0018:ffffc90000007ba8 EFLAGS: 00010246
RAX: ffffffff818ed934 RBX: ffff888032a9f4a0 RCX: ffff88802b0c5b80
RDX: 0000000000000100 RSI: 0000000000000004 RDI: 0000000000000000
RBP: 0000000000000004 R08: ffff8880313ac193 R09: 1ffff11006275832
R10: dffffc0000000000 R11: ffffed1006275833 R12: dffffc0000000000
R13: ffff888032a9f400 R14: ffff8880313ac000 R15: ffff8880313ac190
FS:  0000000000000000(0000) GS:ffff888125ec2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa4d045d000 CR3: 0000000076ba6000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x286/0x870 kernel/softirq.c:626
 __do_softirq kernel/softirq.c:660 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 9b 9e d7 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000564f220 EFLAGS: 00000206
RAX: 02ca7c4d00139400 RBX: 0000000000000000 RCX: 02ca7c4d00139400
RDX: 0000000000000000 RSI: ffffffff8d96e376 RDI: ffffffff8bbf41e0
RBP: ffffffff8230935f R08: 0000000000000000 R09: ffffffff8230935f
R10: dffffc0000000000 R11: fffff9400032c7af R12: 0000000000000002
R13: ffffffff8df3b720 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 __lruvec_stat_mod_folio+0x8b/0x2e0 mm/memcontrol.c:787
 __folio_mod_stat mm/rmap.c:1215 [inline]
 __folio_remove_rmap mm/rmap.c:1752 [inline]
 folio_remove_rmap_ptes+0x387/0x1060 mm/rmap.c:1779
 zap_present_folio_ptes mm/memory.c:1654 [inline]
 zap_present_ptes mm/memory.c:1712 [inline]
 do_zap_pte_range mm/memory.c:1814 [inline]
 zap_pte_range mm/memory.c:1858 [inline]
 zap_pmd_range mm/memory.c:1950 [inline]
 zap_pud_range mm/memory.c:1979 [inline]
 zap_p4d_range mm/memory.c:2000 [inline]
 unmap_page_range+0x1e5e/0x4140 mm/memory.c:2021
 unmap_single_vma mm/memory.c:2064 [inline]
 unmap_vmas+0x399/0x580 mm/memory.c:2108
 exit_mmap+0x240/0xb40 mm/mmap.c:1277
 __mmput+0x118/0x430 kernel/fork.c:1132
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x650/0x2300 kernel/exit.c:958
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1111
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f54bc18f6c9
Code: Unable to access opcode bytes at 0x7f54bc18f69f.
RSP: 002b:00007f54bd0a6fe8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007f54bc3e5fa0 RCX: 00007f54bc18f6c9
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 498144ee5f62e049
RBP: 00007f54bc211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f54bc3e6038 R14: 00007f54bc3e5fa0 R15: 00007ffe1116b2d8
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	9c                   	pushf
   5:	8f 44 24 30          	pop    0x30(%rsp)
   9:	f7 44 24 30 00 02 00 	testl  $0x200,0x30(%rsp)
  10:	00
  11:	0f 85 cd 00 00 00    	jne    0xe4
  17:	f7 44 24 08 00 02 00 	testl  $0x200,0x8(%rsp)
  1e:	00
  1f:	74 01                	je     0x22
  21:	fb                   	sti
  22:	65 48 8b 05 9b 9e d7 	mov    %gs:0x10d79e9b(%rip),%rax        # 0x10d79ec5
  29:	10
* 2a:	48 3b 44 24 58       	cmp    0x58(%rsp),%rax <-- trapping instruction
  2f:	0f 85 f2 00 00 00    	jne    0x127
  35:	48 83 c4 60          	add    $0x60,%rsp
  39:	5b                   	pop    %rbx
  3a:	41 5c                	pop    %r12
  3c:	41 5d                	pop    %r13
  3e:	41 5e                	pop    %r14