__x64_sys_readlinkat+0xb7/0x100
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
------------[ cut here ]------------
percpu ref (css_release) <= 0 (-2451) after switching to atomic
WARNING: lib/percpu-refcount.c:197 at percpu_ref_switch_to_atomic_rcu+0x3cc/0x480, CPU#0: syz-executor.1/283
Modules linked in:
CPU: 0 UID: 0 PID: 283 Comm: syz-executor.1 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:ffff88806ce08e38 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8139de70
RDX: ffff888017239b80 RSI: ffffffff8139de7e RDI: 0000000000000001
RBP: 7ffffffffffff66d R08: 0000000000000001 R09: ffffed100d9c4801
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888013eab780
R13: ffff888013eab7a0 R14: 0000000000000002 R15: 0000000000000003
FS:  00005555772d1400(0000) GS:ffff8880e55d8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2cf24000 CR3: 00000000399aa000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 rcu_core+0x7c8/0x1800
 handle_softirqs+0x1b1/0x770
 do_softirq+0x48/0x80
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf1/0x110
 kernel_fpu_end+0x5e/0x70
 crc32c+0x2d0/0x350
 ext4_handle_dirty_dirblock+0x26a/0x370
 ext4_delete_entry+0x34c/0x430
 __ext4_unlink+0x7a7/0xcd0
 ext4_unlink+0x429/0x5a0
 vfs_unlink+0x35e/0x9d0
 do_unlinkat+0x4ad/0x670
 __x64_sys_unlink+0xc7/0x110
 do_syscall_64+0xbf/0x360
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c43ed8457
Code: 73 01 c3 48 c7 c1 bc ff ff ff 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 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc1bdf6118 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2c43ed8457
RDX: 00007ffc1bdf6150 RSI: 00007ffc1bdf6150 RDI: 00007ffc1bdf61e0
RBP: 00007ffc1bdf61e0 R08: 0000000000000001 R09: 00007ffc1bdf5fb0
R10: 00005555772d2c7b R11: 0000000000000206 R12: 00007f2c43f32105
R13: 00007ffc1bdf72a0 R14: 00005555772d2c20 R15: 00007ffc1bdf72e0
 </TASK>
irq event stamp: 2003964
hardirqs last  enabled at (2003976): [<ffffffff81541b18>] __up_console_sem+0x78/0x80
hardirqs last disabled at (2003985): [<ffffffff81541afd>] __up_console_sem+0x5d/0x80
softirqs last  enabled at (2003326): [<ffffffff812c76d9>] kernel_fpu_end+0x59/0x70
softirqs last disabled at (2003327): [<ffffffff813bb958>] do_softirq+0x48/0x80
---[ end trace 0000000000000000 ]---
percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff888013eab780 pointer offset 0 size 64
percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff88800b991200 pointer offset 0 size 64
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
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
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