------------[ cut here ]------------ percpu ref (free_ioctx_reqs) <= 0 (0) after switching to atomic WARNING: lib/percpu-refcount.c:197 at percpu_ref_switch_to_atomic_rcu+0x3cc/0x480, CPU#0: ksoftirqd/0/14 Modules linked in: CPU: 0 UID: 0 PID: 14 Comm: ksoftirqd/0 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:ffff888009617c70 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8139de70 RDX: ffff888009601b80 RSI: ffffffff8139de7e RDI: 0000000000000001 RBP: 8000000000000000 R08: 0000000000000001 R09: ffffed100d9c4801 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800e621000 R13: ffff88800e621020 R14: 0000000000000002 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880e55d8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7f09f50570 CR3: 000000003bc36000 CR4: 0000000000350ef0 Call Trace: rcu_core+0x7c8/0x1800 handle_softirqs+0x1b1/0x770 run_ksoftirqd+0x2e/0x60 smpboot_thread_fn+0x41d/0x9d0 kthread+0x3c8/0x740 ret_from_fork+0x34b/0x430 ret_from_fork_asm+0x1a/0x30 irq event stamp: 6177568 hardirqs last enabled at (6177576): [] __up_console_sem+0x78/0x80 hardirqs last disabled at (6177583): [] __up_console_sem+0x5d/0x80 softirqs last enabled at (6177146): [] handle_softirqs+0x50c/0x770 softirqs last disabled at (6177151): [] run_ksoftirqd+0x2e/0x60 ---[ end trace 0000000000000000 ]--- percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff88800e621000 pointer offset 0 size 64 kmemleak: Found object by alias at 0x607f1a63e264 CPU: 0 UID: 0 PID: 6803 Comm: syz-executor.3 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 Call Trace: dump_stack_lvl+0xca/0x120 __lookup_object+0x94/0xb0 delete_object_full+0x27/0x70 free_percpu+0x30/0x1160 futex_hash_free+0x38/0xc0 mmput+0x2d3/0x390 copy_process+0x273d/0x73c0 kernel_clone+0xea/0x7f0 __do_sys_clone3+0x1f5/0x280 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f455d440b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f455a995188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3 RAX: ffffffffffffffda RBX: 00007f455d554020 RCX: 00007f455d440b19 RDX: 0000000000000000 RSI: 0000000000000058 RDI: 0000000020002b80 RBP: 00007f455d49af6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe51c1520f R14: 00007f455a995300 R15: 0000000000022000 kmemleak: Object (percpu) 0x607f1a63e260 (size 8): kmemleak: comm "syz-executor.2", pid 6818, jiffies 4295260068 kmemleak: min_count = 1 kmemleak: count = 0 kmemleak: flags = 0x21 kmemleak: checksum = 0 kmemleak: backtrace: pcpu_alloc_noprof+0x87a/0x1170 percpu_ref_init+0x37/0x400 ioctx_alloc+0x368/0x1e10 __x64_sys_io_setup+0xc8/0x1f0 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f kmemleak: Found object by alias at 0x607f1a63e264 CPU: 0 UID: 0 PID: 6796 Comm: syz-executor.3 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 Call Trace: dump_stack_lvl+0xca/0x120 __lookup_object+0x94/0xb0 delete_object_full+0x27/0x70 free_percpu+0x30/0x1160 futex_hash_free+0x38/0xc0 mmput+0x2d3/0x390 do_exit+0x79d/0x2970 do_group_exit+0xd3/0x2a0 get_signal+0x2315/0x2340 arch_do_signal_or_restart+0x80/0x790 exit_to_user_mode_loop+0x8b/0x110 do_syscall_64+0x2f7/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f455d440b19 Code: Unable to access opcode bytes at 0x7f455d440aef. RSP: 002b:00007f455a9b6218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f455d553f68 RCX: 00007f455d440b19 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f455d553f68 RBP: 00007f455d553f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f455d553f6c R13: 00007ffe51c1520f R14: 00007f455a9b6300 R15: 0000000000022000 kmemleak: Object (percpu) 0x607f1a63e260 (size 8): kmemleak: comm "syz-executor.2", pid 6818, jiffies 4295260068 kmemleak: min_count = 1 kmemleak: count = 0 kmemleak: flags = 0x21 kmemleak: checksum = 0 kmemleak: backtrace: pcpu_alloc_noprof+0x87a/0x1170 percpu_ref_init+0x37/0x400 ioctx_alloc+0x368/0x1e10 __x64_sys_io_setup+0xc8/0x1f0 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f