------------[ cut here ]------------
ida_free called for id=1004 which is not allocated.
WARNING: CPU: 0 PID: 36 at lib/idr.c:592 ida_free+0x1f9/0x2e0 lib/idr.c:592
Modules linked in:
CPU: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Tainted: G     U              syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: netns cleanup_net
RIP: 0010:ida_free+0x1f9/0x2e0 lib/idr.c:592
Code: 76 f6 41 83 fe 3e 76 72 e8 24 78 76 f6 48 8b 7c 24 28 4c 89 ee e8 07 39 0d 00 90 48 c7 c7 00 ba cf 8c 89 ee e8 e8 52 35 f6 90 <0f> 0b 90 90 e8 fe 77 76 f6 48 b8 00 00 00 00 00 fc ff df 48 01 c3
RSP: 0018:ffffc90000ac78e0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 1ffff92000158f1d RCX: ffffffff81796528
RDX: ffff888142ae9e40 RSI: ffffffff81796535 RDI: 0000000000000001
RBP: 00000000000003ec R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88801e6d2000
R13: 0000000000000293 R14: 00000000000003ec R15: ffff88801e6d2078
FS:  0000000000000000(0000) GS:ffff888124e5d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49647e7dac CR3: 000000002766c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 proc_free_inum fs/proc/generic.c:216 [inline]
 pde_put fs/proc/generic.c:696 [inline]
 pde_put+0xa9/0x1d0 fs/proc/generic.c:693
 remove_proc_entry+0x2d3/0x530 fs/proc/generic.c:739
 proc_net_ns_exit+0x3f/0x80 fs/proc/proc_net.c:404
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
 cleanup_net+0x41b/0x8b0 net/core/net_namespace.c:695
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>