------------[ cut here ]------------
ida_free called for id=2064 which is not allocated.
WARNING: CPU: 1 PID: 8375 at lib/idr.c:592 ida_free+0x280/0x310 lib/idr.c:592
Modules linked in:
CPU: 1 UID: 0 PID: 8375 Comm: syz.1.539 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:ida_free+0x280/0x310 lib/idr.c:592
Code: 00 00 00 00 fc ff df 48 8b 5c 24 10 48 8b 7c 24 40 48 89 de e8 81 2c 0c 00 90 48 c7 c7 20 27 74 8c 44 89 fe e8 91 1c 59 f6 90 <0f> 0b 90 90 eb 34 e8 75 ae 95 f6 49 bd 00 00 00 00 00 fc ff df eb
RSP: 0018:ffffc9001b77f880 EFLAGS: 00010246
RAX: 719c7f66327e8c00 RBX: 0000000000000a06 RCX: ffff88802a56bc80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc9001b77f968 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1b7a118 R12: 1ffff920036eff14
R13: dffffc0000000000 R14: ffff8880794dcc00 R15: 0000000000000810
FS:  0000000000000000(0000) GS:ffff88812649b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000440 CR3: 000000004ccce000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 free_mnt_ns+0x52/0xe0 fs/namespace.c:4096
 namespace_unlock+0x529/0x760 fs/namespace.c:1701
 free_nsproxy+0x3e/0x350 kernel/nsproxy.c:188
 do_exit+0x6b0/0x2300 kernel/exit.c:960
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x72/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f419058eec9
Code: Unable to access opcode bytes at 0x7f419058ee9f.
RSP: 002b:00007f4191486038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: fffffffffffffff4 RBX: 00007f41907e5fa0 RCX: 00007f419058eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000026020480
RBP: 00007f4190611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f41907e6038 R14: 00007f41907e5fa0 R15: 00007ffc100e3638
 </TASK>