------------[ cut here ]------------ percpu ref (free_ioctx_reqs) <= 0 (-2) after switching to atomic WARNING: lib/percpu-refcount.c:197 at percpu_ref_switch_to_atomic_rcu+0x3cc/0x480, CPU#0: syz-executor.0/273 Modules linked in: CPU: 0 UID: 0 PID: 273 Comm: syz-executor.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:ffff88806ce08e20 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8139de70 RDX: ffff88801949d280 RSI: ffffffff8139de7e RDI: 0000000000000001 RBP: 7ffffffffffffffe R08: 0000000000000001 R09: ffffed100d9c4801 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800d27c100 R13: ffff88800d27c120 R14: 0000000000000002 R15: 0000000000000003 FS: 0000555574cc1400(0000) GS:ffff8880e55d8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d128000 CR3: 0000000034105000 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:_raw_spin_unlock_irqrestore+0x34/0x50 Code: c7 18 53 48 89 f3 48 8b 74 24 10 e8 16 a5 93 fc 48 89 ef e8 4e f0 93 fc 80 e7 02 74 06 e8 e4 07 be fc fb 65 ff 0d 6c 4c c6 02 <74> 07 5b 5d e9 33 23 00 00 0f 1f 44 00 00 5b 5d e9 27 23 00 00 0f RSP: 0018:ffff888016f978b0 EFLAGS: 00000286 RAX: 000000000002aa21 RBX: 0000000000000286 RCX: 0000000000000040 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84be33bc RBP: ffffffff85d09560 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8643b457 R11: 0000000000000001 R12: ffff888044743dc0 R13: 0000000000000100 R14: 0000000000000001 R15: 0000000000000286 __create_object+0x59/0x80 kmem_cache_alloc_noprof+0x414/0x690 vm_area_dup+0x25/0x6f0 dup_mmap+0x80d/0x1d10 copy_process+0x3ad5/0x73c0 kernel_clone+0xea/0x7f0 __do_sys_clone+0xce/0x120 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe82726910b Code: ed 0f 85 60 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31 c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 89 00 00 00 41 89 c5 85 c0 0f 85 90 00 00 RSP: 002b:00007ffcf786c470 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe82726910b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000555574cc1400 R10: 0000555574cc16d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffcf786c550 irq event stamp: 175356 hardirqs last enabled at (175364): [] __up_console_sem+0x78/0x80 hardirqs last disabled at (175375): [] __up_console_sem+0x5d/0x80 softirqs last enabled at (174306): [] tcp_close+0x30/0x110 softirqs last disabled at (174627): [] __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 ffff88800d27c100 pointer offset 0 size 64 kmemleak: Found object by alias at 0x607f1a63de30 CPU: 0 UID: 0 PID: 273 Comm: syz-executor.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 Call Trace: dump_stack_lvl+0xca/0x120 __lookup_object+0x94/0xb0 delete_object_full+0x27/0x70 free_percpu+0x30/0x1160 __percpu_ref_exit+0xa9/0x100 percpu_ref_switch_to_atomic_rcu+0x2e5/0x480 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:_raw_spin_unlock_irqrestore+0x34/0x50 Code: c7 18 53 48 89 f3 48 8b 74 24 10 e8 16 a5 93 fc 48 89 ef e8 4e f0 93 fc 80 e7 02 74 06 e8 e4 07 be fc fb 65 ff 0d 6c 4c c6 02 <74> 07 5b 5d e9 33 23 00 00 0f 1f 44 00 00 5b 5d e9 27 23 00 00 0f RSP: 0018:ffff888016f978b0 EFLAGS: 00000286 RAX: 000000000002aa21 RBX: 0000000000000286 RCX: 0000000000000040 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff84be33bc RBP: ffffffff85d09560 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8643b457 R11: 0000000000000001 R12: ffff888044743dc0 R13: 0000000000000100 R14: 0000000000000001 R15: 0000000000000286 __create_object+0x59/0x80 kmem_cache_alloc_noprof+0x414/0x690 vm_area_dup+0x25/0x6f0 dup_mmap+0x80d/0x1d10 copy_process+0x3ad5/0x73c0 kernel_clone+0xea/0x7f0 __do_sys_clone+0xce/0x120 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe82726910b Code: ed 0f 85 60 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31 c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 89 00 00 00 41 89 c5 85 c0 0f 85 90 00 00 RSP: 002b:00007ffcf786c470 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe82726910b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000555574cc1400 R10: 0000555574cc16d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffcf786c550 kmemleak: Object (percpu) 0x607f1a63de28 (size 16): kmemleak: comm "syz-executor.0", pid 273, jiffies 4294781718 kmemleak: min_count = 1 kmemleak: count = 0 kmemleak: flags = 0x21 kmemleak: checksum = 0 kmemleak: backtrace: pcpu_alloc_noprof+0x87a/0x1170 mm_init+0x99b/0x1170 copy_process+0x3ab7/0x73c0 kernel_clone+0xea/0x7f0 __do_sys_clone+0xce/0x120 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f kmemleak: Cannot insert 0x607f1a63de30 into the object search tree (overlaps existing) CPU: 0 UID: 0 PID: 3994 Comm: syz-executor.2 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 __link_object+0x190/0x210 __create_object+0x48/0x80 pcpu_alloc_noprof+0x87a/0x1170 alloc_vfsmnt+0x135/0x6e0 clone_mnt+0x6c/0xb70 copy_tree+0x105/0xaf0 copy_mnt_ns+0x1ab/0xab0 create_new_namespaces+0xd6/0xab0 unshare_nsproxy_namespaces+0xc0/0x200 ksys_unshare+0x468/0xa10 __x64_sys_unshare+0x31/0x40 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f716d876b19 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:00007f716adec188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f716d989f60 RCX: 00007f716d876b19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000008020080 RBP: 00007f716d8d0f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe65c15c2f R14: 00007f716adec300 R15: 0000000000022000 kmemleak: Kernel memory leak detector disabled kmemleak: Object (percpu) 0x607f1a63de28 (size 16): kmemleak: comm "syz-executor.0", pid 273, jiffies 4294781718 kmemleak: min_count = 1 kmemleak: count = 0 kmemleak: flags = 0x21 kmemleak: checksum = 0 kmemleak: backtrace: pcpu_alloc_noprof+0x87a/0x1170 mm_init+0x99b/0x1170 copy_process+0x3ab7/0x73c0 kernel_clone+0xea/0x7f0 __do_sys_clone+0xce/0x120 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f kmemleak: Found object by alias at 0x607f1a63de34 CPU: 0 UID: 0 PID: 3993 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: 0033:0x7f2e9e5f4b19 Code: Unable to access opcode bytes at 0x7f2e9e5f4aef. RSP: 002b:00007f2e9bb6a218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f2e9e707f68 RCX: 00007f2e9e5f4b19 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f2e9e707f6c RBP: 00007f2e9e707f60 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2e9e707f6c R13: 00007ffc25e4967f R14: 00007f2e9bb6a300 R15: 0000000000022000 kmemleak: Object (percpu) 0x607f1a63de28 (size 16): kmemleak: comm "syz-executor.0", pid 273, jiffies 4294781718 kmemleak: min_count = 1 kmemleak: count = 0 kmemleak: flags = 0x21 kmemleak: checksum = 0 kmemleak: backtrace: pcpu_alloc_noprof+0x87a/0x1170 mm_init+0x99b/0x1170 copy_process+0x3ab7/0x73c0 kernel_clone+0xea/0x7f0 __do_sys_clone+0xce/0x120 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f ------------[ cut here ]------------ WARNING: fs/namespace.c:1434 at mntput_no_expire+0x78e/0xbe0, CPU#0: syz-executor.2/3994 Modules linked in: CPU: 0 UID: 0 PID: 3994 Comm: syz-executor.2 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:mntput_no_expire+0x78e/0xbe0 Code: 05 d6 30 81 04 01 e8 71 df 91 ff e9 41 fc ff ff e8 27 47 b4 ff 31 ff 44 89 ee e8 4d 42 b4 ff 45 85 ed 79 09 e8 13 47 b4 ff 90 <0f> 0b 90 e8 0a 47 b4 ff e8 b5 2d fc 02 31 ff 89 c5 89 c6 e8 2a 42 RSP: 0018:ffff88801956f9c0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 1ffff110032adf3d RCX: ffffffff81bfaf93 RDX: ffff88804431d280 RSI: ffffffff81bfaf9d RDI: 0000000000000005 RBP: ffff88800d7256c0 R08: 0000000000000001 R09: 0000000000000000 R10: 00000000fffffffd R11: 0000000000000001 R12: ffff88801956fa28 R13: 00000000fffffffd R14: dead000000000100 R15: ffff88800d7256c0 FS: 0000000000000000(0000) GS:ffff8880e55d8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2cb25000 CR3: 0000000005a88000 CR4: 0000000000350ef0 Call Trace: namespace_unlock+0x7f1/0x810 put_mnt_ns+0xf5/0x120 free_nsproxy+0x3a/0x400 switch_task_namespaces+0xe2/0x100 do_exit+0x841/0x2970 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: 0033:0x7f716d876b19 Code: Unable to access opcode bytes at 0x7f716d876aef. RSP: 002b:00007f716adec218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f716d989f68 RCX: 00007f716d876b19 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f716d989f68 RBP: 00007f716d989f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f716d989f6c R13: 00007ffe65c15c2f R14: 00007f716adec300 R15: 0000000000022000 irq event stamp: 2225 hardirqs last enabled at (2233): [] __up_console_sem+0x78/0x80 hardirqs last disabled at (2242): [] __up_console_sem+0x5d/0x80 softirqs last enabled at (2176): [] handle_softirqs+0x50c/0x770 softirqs last disabled at (1985): [] __irq_exit_rcu+0xc4/0x100 ---[ end trace 0000000000000000 ]--- kmemleak: Automatic memory scanning thread ended ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 18 53 48 sbb %dl,0x48(%rbx) 3: 89 f3 mov %esi,%ebx 5: 48 8b 74 24 10 mov 0x10(%rsp),%rsi a: e8 16 a5 93 fc callq 0xfc93a525 f: 48 89 ef mov %rbp,%rdi 12: e8 4e f0 93 fc callq 0xfc93f065 17: 80 e7 02 and $0x2,%bh 1a: 74 06 je 0x22 1c: e8 e4 07 be fc callq 0xfcbe0805 21: fb sti 22: 65 ff 0d 6c 4c c6 02 decl %gs:0x2c64c6c(%rip) # 0x2c64c95 * 29: 74 07 je 0x32 <-- trapping instruction 2b: 5b pop %rbx 2c: 5d pop %rbp 2d: e9 33 23 00 00 jmpq 0x2365 32: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 37: 5b pop %rbx 38: 5d pop %rbp 39: e9 27 23 00 00 jmpq 0x2365 3e: 0f .byte 0xf