------------[ cut here ]------------
WARNING: ./include/linux/ns_common.h:255 at __ns_ref_put include/linux/ns_common.h:255 [inline], CPU#1: syz.0.13/5943
WARNING: ./include/linux/ns_common.h:255 at put_user_ns include/linux/user_namespace.h:189 [inline], CPU#1: syz.0.13/5943
WARNING: ./include/linux/ns_common.h:255 at put_cred_rcu+0x2c5/0x340 kernel/cred.c:61, CPU#1: syz.0.13/5943
Modules linked in:
CPU: 1 UID: 0 PID: 5943 Comm: syz.0.13 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:ffffc90000a08ba8 EFLAGS: 00010246
RAX: ffffffff818ed124 RBX: ffff8880273d88a0 RCX: ffff888031000000
RDX: 0000000000000100 RSI: 0000000000000004 RDI: 0000000000000000
RBP: 0000000000000004 R08: ffff88806bc50193 R09: 1ffff1100d78a032
R10: dffffc0000000000 R11: ffffed100d78a033 R12: dffffc0000000000
R13: ffff8880273d8800 R14: ffff88806bc50000 R15: ffff88806bc50190
FS: 0000000000000000(0000) GS:ffff888125b83000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0d4c986286 CR3: 0000000079536000 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:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 bb 9b 1b 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90004607278 EFLAGS: 00000206
RAX: ff5e055e4b63ea00 RBX: 0000000000000000 RCX: ff5e055e4b63ea00
RDX: 0000000000000000 RSI: ffffffff8dc71a48 RDI: ffffffff8be11160
RBP: ffffffff823391ca R08: 0000000000000000 R09: ffffffff823391ca
R10: dffffc0000000000 R11: fffff940003354d9 R12: 0000000000000002
R13: ffffffff8e33d920 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:958 [inline]
pfn_valid+0xd6/0x490 include/linux/mmzone.h:2183
page_table_check_clear+0x21/0x700 mm/page_table_check.c:70
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:725 [inline]
zap_present_folio_ptes mm/memory.c:1630 [inline]
zap_present_ptes mm/memory.c:1712 [inline]
do_zap_pte_range mm/memory.c:1814 [inline]
zap_pte_range mm/memory.c:1858 [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+0x322d/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: 0033:0x7fe4ac18f6c9
Code: Unable to access opcode bytes at 0x7fe4ac18f69f.
RSP: 002b:00007fe4aa3d4fe8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007fe4ac3e6090 RCX: 00007fe4ac18f6c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000fdba2080
RBP: 00007fe4ac211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fe4ac3e6128 R14: 00007fe4ac3e6090 R15: 00007fffda6e0d88
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 9c pushf
5: 8f 44 24 30 pop 0x30(%rsp)
9: f7 44 24 30 00 02 00 testl $0x200,0x30(%rsp)
10: 00
11: 0f 85 cd 00 00 00 jne 0xe4
17: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp)
1e: 00
1f: 74 01 je 0x22
21: fb sti
22: 65 48 8b 05 bb 9b 1b mov %gs:0x111b9bbb(%rip),%rax # 0x111b9be5
29: 11
* 2a: 48 3b 44 24 58 cmp 0x58(%rsp),%rax <-- trapping instruction
2f: 0f 85 f2 00 00 00 jne 0x127
35: 48 83 c4 60 add $0x60,%rsp
39: 5b pop %rbx
3a: 41 5c pop %r12
3c: 41 5d pop %r13
3e: 41 5e pop %r14