------------[ cut here ]------------ percpu ref (obj_cgroup_release) <= 0 (-343) after switching to atomic WARNING: lib/percpu-refcount.c:197 at percpu_ref_switch_to_atomic_rcu+0x3cc/0x480, CPU#0: syz-executor/9048 Modules linked in: CPU: 0 UID: 0 PID: 9048 Comm: syz-executor Tainted: G W 6.17.0-rc3-next-20250829 #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 80 97 e2 84 e8 75 c5 e9 fe 90 <0f> 0b 90 90 e9 2b ff ff ff e8 f6 de 5f ff e9 9e fe ff ff e8 7c df RSP: 0018:ffff88806ce08e20 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8139de70 RDX: ffff88801bac1b80 RSI: ffffffff8139de7e RDI: 0000000000000001 RBP: 7ffffffffffffea8 R08: 0000000000000001 R09: ffffed100d9c117f R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801dc5a000 R13: ffff88801dc5a020 R14: 0000000000000002 R15: 0000000000000003 FS: 000055556bd41400(0000) GS:ffff8880e55dd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffebd91b000 CR3: 000000001643a000 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:lock_acquire+0x5b/0x2f0 Code: 30 31 c0 66 90 65 8b 05 e7 53 32 06 89 c0 48 0f a3 05 f9 cf f1 04 0f 82 3a 01 00 00 8b 35 d1 db f1 04 85 f6 0f 85 84 00 00 00 <48> 8b 44 24 30 65 48 2b 05 90 53 32 06 0f 85 6e 02 00 00 48 83 c4 RSP: 0018:ffff888018227bd0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 591c5957d3df2b5a RDX: 0000000097dfeaba RSI: 0000000024e2f2fe RDI: 000000001edaaf5d RBP: ffffffff85c1c6a0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000200 kmemleak_scan+0x344/0xe00 kmemleak_write+0x410/0x4f0 full_proxy_write+0x133/0x1a0 vfs_write+0x2b7/0x1150 ksys_write+0x121/0x240 do_syscall_64+0xbf/0x360 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd491ebc5c3 Code: 16 00 00 00 eb ae 90 b8 6e 00 00 00 eb a6 e8 44 ef 04 00 0f 1f 40 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 18 RSP: 002b:00007fff5f3222c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fff5f322908 RCX: 00007fd491ebc5c3 RDX: 0000000000000004 RSI: 00007fd491f72ed9 RDI: 0000000000000003 RBP: 0000000000000003 R08: 001ef18342db3228 R09: 00007fd491ff9000 R10: 00007fd491ff9010 R11: 0000000000000246 R12: 00007fd491ebeb10 R13: 00007fff5f323ee7 R14: 0000000000000000 R15: 00000000000dd900 irq event stamp: 649202 hardirqs last enabled at (649212): [] __up_console_sem+0x78/0x80 hardirqs last disabled at (649221): [] __up_console_sem+0x5d/0x80 softirqs last enabled at (648068): [] handle_softirqs+0x50c/0x770 softirqs last disabled at (648475): [] __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 ffff88801dc5a000 pointer offset 0 size 64 percpu_ref_switch_to_atomic_rcu: percpu_ref_switch_to_atomic_rcu(): percpu_ref underflow slab kmalloc-64 start ffff88800cc9ba00 pointer offset 0 size 64 ---------------- Code disassembly (best guess): 0: 30 31 xor %dh,(%rcx) 2: c0 66 90 65 shlb $0x65,-0x70(%rsi) 6: 8b 05 e7 53 32 06 mov 0x63253e7(%rip),%eax # 0x63253f3 c: 89 c0 mov %eax,%eax e: 48 0f a3 05 f9 cf f1 bt %rax,0x4f1cff9(%rip) # 0x4f1d00f 15: 04 16: 0f 82 3a 01 00 00 jb 0x156 1c: 8b 35 d1 db f1 04 mov 0x4f1dbd1(%rip),%esi # 0x4f1dbf3 22: 85 f6 test %esi,%esi 24: 0f 85 84 00 00 00 jne 0xae * 2a: 48 8b 44 24 30 mov 0x30(%rsp),%rax <-- trapping instruction 2f: 65 48 2b 05 90 53 32 sub %gs:0x6325390(%rip),%rax # 0x63253c7 36: 06 37: 0f 85 6e 02 00 00 jne 0x2ab 3d: 48 rex.W 3e: 83 .byte 0x83 3f: c4 .byte 0xc4