------------[ cut here ]------------ ida_free called for id=4796 which is not allocated. WARNING: CPU: 0 PID: 15551 at lib/idr.c:592 ida_free+0x280/0x310 lib/idr.c:592 Modules linked in: CPU: 0 UID: 0 PID: 15551 Comm: syz.6.2388 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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 21 50 0c 00 90 48 c7 c7 40 ce 94 8c 44 89 fe e8 11 30 47 f6 90 <0f> 0b 90 90 eb 34 e8 65 13 84 f6 49 bd 00 00 00 00 00 fc ff df eb RSP: 0018:ffffc9001bb5f880 EFLAGS: 00010246 RAX: 88f16b9453bc1500 RBX: 0000000000000a06 RCX: ffff88802ac41e40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: ffffc9001bb5f968 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1bfa138 R12: 1ffff9200376bf14 R13: dffffc0000000000 R14: ffff88805a00d800 R15: 00000000000012bc FS: 0000000000000000(0000) GS:ffff888125d3b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000003583e000 CR4: 00000000003526f0 Call Trace: 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/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f46b0b8eec9 Code: Unable to access opcode bytes at 0x7f46b0b8ee9f. RSP: 002b:00007f46b19a1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: fffffffffffffff4 RBX: 00007f46b0de6180 RCX: 00007f46b0b8eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000026020480 RBP: 00007f46b0c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f46b0de6218 R14: 00007f46b0de6180 R15: 00007ffe2c1af238