------------[ cut here ]------------ WARNING: ./include/linux/ns_common.h:255 at __ns_ref_put include/linux/ns_common.h:255 [inline], CPU#0: udevd/5193 WARNING: ./include/linux/ns_common.h:255 at put_user_ns include/linux/user_namespace.h:189 [inline], CPU#0: udevd/5193 WARNING: ./include/linux/ns_common.h:255 at put_cred_rcu+0x2c5/0x340 kernel/cred.c:61, CPU#0: udevd/5193 Modules linked in: CPU: 0 UID: 0 PID: 5193 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__ns_ref_put include/linux/ns_common.h:255 [inline] RIP: 0010:put_user_ns include/linux/user_namespace.h:189 [inline] RIP: 0010:put_cred_rcu+0x2c5/0x340 kernel/cred.c:61 Code: 5c 41 5d 41 5e 41 5f 5d e9 78 8c 8d 00 e8 03 8c 32 00 4c 89 e7 be 03 00 00 00 e8 b6 d6 08 03 e9 b8 fe ff ff e8 ec 8b 32 00 90 <0f> 0b 90 eb 9f e8 e1 8b 32 00 4c 89 ff be 03 00 00 00 e8 94 d6 08 RSP: 0018:ffffc90000007ba8 EFLAGS: 00010246 RAX: ffffffff818ed124 RBX: ffff8880260e07a0 RCX: ffff88807e208000 RDX: 0000000000000100 RSI: 0000000000000004 RDI: 0000000000000000 RBP: 0000000000000004 R08: ffff888060de45bb R09: 1ffff1100c1bc8b7 R10: dffffc0000000000 R11: ffffed100c1bc8b8 R12: dffffc0000000000 R13: ffff8880260e0700 R14: ffff888060de4428 R15: ffff888060de45b8 FS: 00007f68e2da5880(0000) GS:ffff888125a83000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558aacb5c8 CR3: 000000007f05a000 CR4: 00000000003526f0 Call Trace: rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x286/0x870 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1055 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1055 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 eb a0 64 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 53 4c 2c f6 65 8b 05 4c 50 55 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90003387660 EFLAGS: 00000206 RAX: 3e32342a05290d00 RBX: 0000000000000a06 RCX: 3e32342a05290d00 RDX: 0000000000000007 RSI: ffffffff8da87adf RDI: 0000000000000001 RBP: ffffc900033876f0 R08: ffffffff8fbf6577 R09: 1ffffffff1f7ecae R10: dffffc0000000000 R11: fffffbfff1f7ecaf R12: dffffc0000000000 R13: ffff888050738000 R14: ffffffff99f349d8 R15: 1ffff92000670ecc __debug_check_no_obj_freed lib/debugobjects.c:1108 [inline] debug_check_no_obj_freed+0x451/0x470 lib/debugobjects.c:1129 free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x4dd/0xd30 mm/page_alloc.c:2948 discard_slab mm/slub.c:3355 [inline] __put_partials+0x146/0x170 mm/slub.c:3899 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3974 __slab_free+0x25b/0x2e0 mm/slub.c:5966 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4968 [inline] slab_alloc_node mm/slub.c:5278 [inline] __do_kmalloc_node mm/slub.c:5671 [inline] __kmalloc_noprof+0x3cf/0x800 mm/slub.c:5684 kmalloc_noprof include/linux/slab.h:961 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822 security_inode_getattr+0x12f/0x330 security/security.c:1869 vfs_getattr fs/stat.c:259 [inline] vfs_fstat fs/stat.c:281 [inline] __do_sys_newfstat fs/stat.c:555 [inline] __se_sys_newfstat fs/stat.c:550 [inline] __x64_sys_newfstat+0xfc/0x200 fs/stat.c:550 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f68e2711ad7 Code: 73 01 c3 48 8b 0d 21 f3 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 05 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 RSP: 002b:00007fff160de378 EFLAGS: 00000202 ORIG_RAX: 0000000000000005 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 00007f68e2711ad7 RDX: 0000000000090800 RSI: 00007fff160de380 RDI: 000000000000000f RBP: 00007fff160de380 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000202 R12: 000055abe056c7b0 R13: 00000000000000fd R14: 000055abac9d8be0 R15: 00007fff160de720 ---------------- Code disassembly (best guess): 0: 74 05 je 0x7 2: e8 eb a0 64 f6 call 0xf664a0f2 7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp) e: 00 00 10: 9c pushf 11: 8f 44 24 20 pop 0x20(%rsp) 15: f6 44 24 21 02 testb $0x2,0x21(%rsp) 1a: 75 4f jne 0x6b 1c: f7 c3 00 02 00 00 test $0x200,%ebx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 53 4c 2c f6 call 0xf62c4c82 <-- trapping instruction 2f: 65 8b 05 4c 50 55 07 mov %gs:0x755504c(%rip),%eax # 0x7555082 36: 85 c0 test %eax,%eax 38: 74 40 je 0x7a 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss