------------[ cut here ]------------ percpu ref (css_release) <= 0 (-1) after switching to atomic WARNING: lib/percpu-refcount.c:197 at percpu_ref_switch_to_atomic_rcu+0x3cc/0x480, CPU#1: systemd/1 Modules linked in: CPU: 1 UID: 0 PID: 1 Comm: systemd Tainted: G W 6.17.0-rc4-next-20250901 #1 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:percpu_ref_switch_to_atomic_rcu+0x3cc/0x480 Code: 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 9e 00 00 00 49 8b 75 e8 48 c7 c7 c0 99 e2 84 e8 25 ac e9 fe 90 <0f> 0b 90 90 e9 2b ff ff ff e8 56 de 5f ff e9 9e fe ff ff e8 dc de RSP: 0018:ffff88806cf08e20 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8139de70 RDX: ffff8880094f8000 RSI: ffffffff8139de7e RDI: 0000000000000001 RBP: 7fffffffffffffff R08: 0000000000000001 R09: ffffed100d9e4801 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801fab3e80 R13: ffff88801fab3ea0 R14: 0000000000000002 R15: 0000000000000003 FS: 00007f55e8bf6900(0000) GS:ffff8880e56d8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcbe714000 CR3: 000000000cd6c000 CR4: 0000000000350ef0 Call Trace: rcu_core+0x7c8/0x1800 handle_softirqs+0x1b1/0x770 __irq_exit_rcu+0xc4/0x100 irq_exit_rcu+0x9/0x20 sysvec_apic_timer_interrupt+0x70/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:unwind_next_frame+0x54c/0x2540 Code: 00 00 48 89 c8 4d 8b 77 48 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 0f b6 34 10 48 8d 41 01 48 89 c7 48 c1 ef 03 0f b6 14 17 <48> 89 cf 83 e7 07 40 38 fe 40 0f 9e c7 40 84 f6 40 0f 95 c6 40 84 RSP: 0018:ffff888009547140 EFLAGS: 00000212 RAX: ffffffff868cfe09 RBX: 0000000000000001 RCX: ffffffff868cfe08 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 1ffffffff0d19fc1 RBP: ffff888009547208 R08: ffffffff868cfe0c R09: 0000000000000000 R10: 000000000003bea3 R11: 000000000002e30a R12: ffff888009547210 R13: ffff8880095471f8 R14: ffff8880095478e8 R15: ffff8880095471b0 arch_stack_walk+0x86/0xf0 stack_trace_save+0x8e/0xc0 kasan_save_stack+0x24/0x50 kasan_record_aux_stack+0x89/0xa0 __call_rcu_common.constprop.0+0x70/0x960 destroy_inode+0x12b/0x1b0 evict+0x532/0x860 iput.part.0+0x541/0x770 iput+0x62/0x80 dentry_unlink_inode+0x2bb/0x4a0 __dentry_kill+0x1d2/0x5f0 shrink_dentry_list+0x13d/0x650 shrink_dcache_parent+0x1c4/0x590 d_invalidate+0x142/0x290 proc_invalidate_siblings_dcache+0x4c4/0x7b0 release_task+0xc5b/0x1870 wait_consider_task+0x2e68/0x3bd0 __do_wait+0x7ad/0x8f0 do_wait+0x19f/0x560 kernel_waitid+0x101/0x170 __do_sys_waitid+0x201/0x240 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f55e93a02c1 Code: 24 0c 89 4c 24 1c e8 de 9a fb ff 8b 74 24 18 8b 7c 24 0c 45 31 c0 41 89 c1 44 8b 54 24 1c 48 8b 54 24 10 b8 f7 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 2f 44 89 cf 89 44 24 0c e8 0b 9b fb ff 8b 44 RSP: 002b:00007ffcbe71bde0 EFLAGS: 00000246 ORIG_RAX: 00000000000000f7 RAX: ffffffffffffffda RBX: 0000556cb9094230 RCX: 00007f55e93a02c1 RDX: 00007ffcbe71be30 RSI: 0000000000004e72 RDI: 0000000000000001 RBP: 00007ffcbe71be30 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 0000556cb911be70 R13: 0000000000000000 R14: 0000556cb911be70 R15: 0000000000000001 irq event stamp: 6014134 hardirqs last enabled at (6014144): [] __up_console_sem+0x78/0x80 hardirqs last disabled at (6014153): [] __up_console_sem+0x5d/0x80 softirqs last enabled at (6012352): [] handle_softirqs+0x50c/0x770 softirqs last disabled at (6012713): [] __irq_exit_rcu+0xc4/0x100 ---[ end trace 0000000000000000 ]--- percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff88801fab3e80 pointer offset 0 size 64 percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff88800d85f800 pointer offset 0 size 64 UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy misc raw-gadget: fail, usb_gadget_register_driver returned -16 misc raw-gadget: fail, usb_gadget_register_driver returned -16 UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy misc raw-gadget: fail, usb_gadget_register_driver returned -16 UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy misc raw-gadget: fail, usb_gadget_register_driver returned -16 UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy misc raw-gadget: fail, usb_gadget_register_driver returned -16 misc raw-gadget: fail, usb_gadget_register_driver returned -16 UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy misc raw-gadget: fail, usb_gadget_register_driver returned -16 UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy UDC core: USB Raw Gadget: couldn't find an available UDC or it's busy misc raw-gadget: fail, usb_gadget_register_driver returned -16 misc raw-gadget: fail, usb_gadget_register_driver returned -16 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 48 89 c8 mov %rcx,%rax 5: 4d 8b 77 48 mov 0x48(%r15),%r14 9: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 10: fc ff df 13: 48 c1 e8 03 shr $0x3,%rax 17: 0f b6 34 10 movzbl (%rax,%rdx,1),%esi 1b: 48 8d 41 01 lea 0x1(%rcx),%rax 1f: 48 89 c7 mov %rax,%rdi 22: 48 c1 ef 03 shr $0x3,%rdi 26: 0f b6 14 17 movzbl (%rdi,%rdx,1),%edx * 2a: 48 89 cf mov %rcx,%rdi <-- trapping instruction 2d: 83 e7 07 and $0x7,%edi 30: 40 38 fe cmp %dil,%sil 33: 40 0f 9e c7 setle %dil 37: 40 84 f6 test %sil,%sil 3a: 40 0f 95 c6 setne %sil 3e: 40 rex 3f: 84 .byte 0x84