------------[ cut here ]------------ ida_free called for id=1272 which is not allocated. WARNING: CPU: 1 PID: 5834 at lib/idr.c:592 ida_free+0x1f9/0x2e0 lib/idr.c:592 Modules linked in: CPU: 1 UID: 0 PID: 5834 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 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: 75 f6 41 83 fe 3e 76 72 e8 44 5b 75 f6 48 8b 7c 24 28 4c 89 ee e8 47 39 0d 00 90 48 c7 c7 e0 cb cf 8c 89 ee e8 38 e6 33 f6 90 <0f> 0b 90 90 e8 1e 5b 75 f6 48 b8 00 00 00 00 00 fc ff df 48 01 c3 RSP: 0000:ffffc90004017980 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 1ffff92000802f31 RCX: ffffffff8179a5b8 RDX: ffff888024c9c900 RSI: ffffffff8179a5c5 RDI: 0000000000000001 RBP: 00000000000004f8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888030a68000 R13: 0000000000000293 R14: 00000000000000f8 R15: ffff888030a68018 FS: 0000000000000000(0000) GS:ffff888124f71000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000f000 CR3: 000000006de0a000 CR4: 00000000003526f0 Call Trace: free_mnt_ns+0xe0/0x110 fs/namespace.c:4096 namespace_unlock+0x542/0x920 fs/namespace.c:1701 put_mnt_ns fs/namespace.c:6135 [inline] put_mnt_ns+0xf5/0x120 fs/namespace.c:6126 free_nsproxy+0x3a/0x400 kernel/nsproxy.c:188 put_nsproxy include/linux/nsproxy.h:107 [inline] switch_task_namespaces+0xeb/0x100 kernel/nsproxy.c:241 do_exit+0x86a/0x2bf0 kernel/exit.c:960 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x7a/0x100 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+0x419/0x4e0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5377f85017 Code: Unable to access opcode bytes at 0x7f5377f84fed. RSP: 002b:00007ffeeda832a0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 00000000000006b9 RCX: 00007f5377f85017 RDX: 0000000040000000 RSI: 00007ffeeda8330c RDI: 00000000ffffffff RBP: 00007ffeeda8330c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000001c5 R13: 0000555588738590 R14: 00000000000c355c R15: 00007ffeeda83360