------------[ cut here ]------------
ida_free called for id=949 which is not allocated.
WARNING: CPU: 0 PID: 28409 at lib/idr.c:592 ida_free+0x1f9/0x2e0 lib/idr.c:592
Modules linked in:
CPU: 0 UID: 0 PID: 28409 Comm: syz.5.4023 Tainted: G     U              syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:ida_free+0x1f9/0x2e0 lib/idr.c:592
Code: 77 f6 41 83 fe 3e 76 72 e8 e4 ca 77 f6 48 8b 7c 24 28 4c 89 ee e8 07 39 0d 00 90 48 c7 c7 c0 c1 cf 8c 89 ee e8 a8 a5 36 f6 90 <0f> 0b 90 90 e8 be ca 77 f6 48 b8 00 00 00 00 00 fc ff df 48 01 c3
RSP: 0018:ffffc900046ffa20 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 1ffff920008dff45 RCX: ffffc9000c47a000
RDX: 0000000000080000 RSI: ffffffff81796535 RDI: 0000000000000001
RBP: 00000000000003b5 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000003a2e0 R12: ffff88814169c000
R13: 0000000000000246 R14: 00000000000003b5 R15: ffff88814169c070
FS:  00007f93bf3686c0(0000) GS:ffff888124e79000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564a0be16e28 CR3: 000000006267e000 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
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x2eb/0xab0 net/core/net_namespace.c:252
 setup_net+0x1e2/0x390 net/core/net_namespace.c:461
 copy_net_ns+0x2f8/0x690 net/core/net_namespace.c:580
 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218
 ksys_unshare+0x45b/0xa40 kernel/fork.c:3132
 __do_sys_unshare kernel/fork.c:3203 [inline]
 __se_sys_unshare kernel/fork.c:3201 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3201
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f93be58eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f93bf368038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f93be7e5fa0 RCX: 00007f93be58eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080
RBP: 00007f93be611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f93be7e6038 R14: 00007f93be7e5fa0 R15: 00007fffd04c6898
 </TASK>