------------[ cut here ]------------ WARNING: CPU: 1 PID: 6618 at kernel/rcu/tree_stall.h:989 rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:989 Modules linked in: CPU: 1 UID: 0 PID: 6618 Comm: syz.4.256 Not tainted 6.15.0-syzkaller-g02670deede22 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:989 Code: ff ff 48 c7 c7 20 64 ac 99 be 04 00 00 00 e8 83 16 7c 00 4c 89 f7 b8 01 00 00 00 87 05 65 aa 04 18 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 00 44 14 8e 74 47 48 c7 c0 30 44 a1 8f 48 c1 e8 RSP: 0018:ffffc90000a08bb8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000a02 RCX: ffffffff81a7b9ad RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e144400 RBP: ffffc90000a08e30 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff3358c84 R12: 0000000000002904 R13: 1ffff110170e7922 R14: ffffffff8e144400 R15: dffffc0000000000 FS: 000055557ab75500(0000) GS:ffff888125d52000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c24b6e8 CR3: 0000000032680000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: rcu_core+0x5f7/0x1710 kernel/rcu/tree.c:2827 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:430 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x6ce/0xb60 kernel/locking/qspinlock.c:325 Code: ff ff 66 c7 84 24 90 00 00 00 00 01 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 20 0f b6 04 01 84 c0 75 46 80 3b 00 74 09 f3 90 <41> ff c6 75 d3 eb 4b 48 89 df be 02 00 00 00 e8 5e 42 bb f6 48 8d RSP: 0018:ffffc9001c5bfb00 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff888148c7f7d8 RCX: 1ffff1102918fefb RDX: 0000000000000000 RSI: ffffffff8d9814e8 RDI: ffff8880b873c894 RBP: ffffc9001c5bfc18 R08: ffffffff8fa112f7 R09: 1ffffffff1f4225e R10: dffffc0000000000 R11: fffffbfff1f4225f R12: 1ffffffff1bf5318 R13: 0000000000000000 R14: 00000000ffffb035 R15: 1ffff1102918fefb pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:351 [inline] lock_for_kill+0xdc/0x210 fs/dcache.c:719 dput+0x18a/0x2b0 fs/dcache.c:909 __fput+0x68e/0xa70 fs/file_table.c:473 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff674b8e929 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff0f904e08 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000001ceb1 RCX: 00007ff674b8e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007ff674db7ba0 R08: 0000000000000001 R09: 000000110f9050ff R10: 00007ff674a00000 R11: 0000000000000246 R12: 00007ff674db5fac R13: 00007ff674db5fa0 R14: ffffffffffffffff R15: 00007fff0f904f20 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 66 c7 84 24 90 00 00 movw $0x100,0x90(%rsp) 7: 00 00 01 a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 11: fc ff df 14: 48 8b 4c 24 20 mov 0x20(%rsp),%rcx 19: 0f b6 04 01 movzbl (%rcx,%rax,1),%eax 1d: 84 c0 test %al,%al 1f: 75 46 jne 0x67 21: 80 3b 00 cmpb $0x0,(%rbx) 24: 74 09 je 0x2f 26: f3 90 pause * 28: 41 ff c6 inc %r14d <-- trapping instruction 2b: 75 d3 jne 0x0 2d: eb 4b jmp 0x7a 2f: 48 89 df mov %rbx,%rdi 32: be 02 00 00 00 mov $0x2,%esi 37: e8 5e 42 bb f6 call 0xf6bb429a 3c: 48 rex.W 3d: 8d .byte 0x8d