------------[ cut here ]------------
WARNING: ./include/linux/ns_common.h:255 at __ns_ref_put include/linux/ns_common.h:255 [inline], CPU#0: syz.3.1037/8669
WARNING: ./include/linux/ns_common.h:255 at put_pid_ns+0x113/0x150 kernel/pid_namespace.c:187, CPU#0: syz.3.1037/8669
Modules linked in:
CPU: 0 UID: 0 PID: 8669 Comm: syz.3.1037 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_pid_ns+0x113/0x150 kernel/pid_namespace.c:187
Code: ab cc ff bf 01 00 00 00 89 ee e8 58 b9 03 00 85 ed 7e 1c e8 0f b5 03 00 5b 41 5e 41 5f 5d c3 cc cc cc cc cc e8 fe b4 03 00 90 <0f> 0b 90 eb 95 e8 f3 b4 03 00 4c 89 f7 be 03 00 00 00 5b 41 5e 41
RSP: 0018:ffffc9000b3bfa68 EFLAGS: 00010293
RAX: ffffffff81be1b32 RBX: ffff88805ae21830 RCX: ffff88802e2a1e80
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000000
RBP: 00000000ffffffff R08: ffff88805ae2199b R09: 1ffff1100b5c4333
R10: dffffc0000000000 R11: ffffed100b5c4334 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff88805ae21998 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125a79000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c32ae18 CR3: 000000006ac38000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 free_nsproxy+0x13a/0x560 kernel/nsproxy.c:195
 do_exit+0x6b8/0x2300 kernel/exit.c:969
 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: 0033:0x7fdfe378f6c9
Code: Unable to access opcode bytes at 0x7fdfe378f69f.
RSP: 002b:00007fdfe45f30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fdfe39e5fa8 RCX: 00007fdfe378f6c9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fdfe39e5fa8
RBP: 00007fdfe39e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdfe39e6038 R14: 00007ffecb593aa0 R15: 00007ffecb593b88
 </TASK>