------------[ cut here ]------------ WARNING: ./include/linux/ns_common.h:255 at __ns_ref_put include/linux/ns_common.h:255 [inline], CPU#1: syz.0.329/7020 WARNING: ./include/linux/ns_common.h:255 at put_user_ns include/linux/user_namespace.h:189 [inline], CPU#1: syz.0.329/7020 WARNING: ./include/linux/ns_common.h:255 at put_cred_rcu+0x2c5/0x340 kernel/cred.c:61, CPU#1: syz.0.329/7020 Modules linked in: CPU: 1 UID: 0 PID: 7020 Comm: syz.0.329 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 b8 25 8e 00 e8 13 a7 32 00 4c 89 e7 be 03 00 00 00 e8 a6 02 02 03 e9 b8 fe ff ff e8 fc a6 32 00 90 <0f> 0b 90 eb 9f e8 f1 a6 32 00 4c 89 ff be 03 00 00 00 e8 84 02 02 RSP: 0018:ffffc90000a08ba8 EFLAGS: 00010246 RAX: ffffffff818ed934 RBX: ffff888026940ba0 RCX: ffff88807a735b80 RDX: 0000000000000100 RSI: 0000000000000004 RDI: 0000000000000000 RBP: 0000000000000004 R08: ffff88805c344193 R09: 1ffff1100b868832 R10: dffffc0000000000 R11: ffffed100b868833 R12: dffffc0000000000 R13: ffff888026940b00 R14: ffff88805c344000 R15: ffff88805c344190 FS: 0000000000000000(0000) GS:ffff888125fc2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9043557240 CR3: 000000000dd36000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 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:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:preempt_count_add+0x6/0x1a0 kernel/sched/core.c:5723 Code: 24 e8 de 68 97 00 eb 8c e9 f1 fe ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 e0 23 81 99 48 c1 RSP: 0018:ffffc900048d71e0 EFLAGS: 00000246 RAX: 1ffff11003950318 RBX: 0000000000000012 RCX: dffffc0000000000 RDX: 00000000ffffffff RSI: 0000000000000012 RDI: 0000000000000001 RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffffff8230935f R10: dffffc0000000000 R11: fffff940002a5bff R12: ffff88801ca81908 R13: 000000000000000f R14: ffff888025131a80 R15: ffff88813fffb400 mod_memcg_lruvec_state+0x7d/0x370 mm/memcontrol.c:744 __mod_lruvec_state mm/memcontrol.c:777 [inline] __lruvec_stat_mod_folio+0x196/0x2e0 mm/memcontrol.c:797 __folio_mod_stat mm/rmap.c:1215 [inline] __folio_remove_rmap mm/rmap.c:1752 [inline] folio_remove_rmap_ptes+0x387/0x1060 mm/rmap.c:1779 tlb_flush_rmap_batch+0x133/0x2d0 mm/mmu_gather.c:66 tlb_flush_rmaps+0x9b/0xf0 mm/mmu_gather.c:89 zap_pte_range mm/memory.c:1886 [inline] zap_pmd_range mm/memory.c:1950 [inline] zap_pud_range mm/memory.c:1979 [inline] zap_p4d_range mm/memory.c:2000 [inline] unmap_page_range+0x3878/0x4140 mm/memory.c:2021 unmap_single_vma mm/memory.c:2064 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2108 exit_mmap+0x240/0xb40 mm/mmap.c:1277 __mmput+0x118/0x430 kernel/fork.c:1132 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x650/0x2300 kernel/exit.c:958 do_group_exit+0x21c/0x2d0 kernel/exit.c:1111 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f9c98f6c9 Code: Unable to access opcode bytes at 0x7f8f9c98f69f. RSP: 002b:00007f8f9d76d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f8f9cbe6188 RCX: 00007f8f9c98f6c9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8f9cbe6188 RBP: 00007f8f9cbe6180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8f9cbe6218 R14: 00007ffd229be870 R15: 00007ffd229be958 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e8 de 68 97 00 call 0x9768e3 5: eb 8c jmp 0xffffff93 7: e9 f1 fe ff ff jmp 0xfffffefd c: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: 90 nop 23: f3 0f 1e fa endbr64 27: 41 57 push %r15 * 29: 41 56 push %r14 <-- trapping instruction 2b: 53 push %rbx 2c: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15 33: fc ff df 36: 48 c7 c0 e0 23 81 99 mov $0xffffffff998123e0,%rax 3d: 48 rex.W 3e: c1 .byte 0xc1