------------[ cut here ]------------ WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049, CPU#1: syz.1.915/9954 Modules linked in: CPU: 1 UID: 0 PID: 9954 Comm: syz.1.915 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049 Code: ff ff 48 c7 c7 a0 05 8e 99 be 04 00 00 00 e8 03 db 7f 00 4c 89 f7 b8 01 00 00 00 87 05 55 d2 e5 17 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff c0 6d f4 8d 74 47 48 c7 c0 a0 33 82 8f 48 c1 e8 RSP: 0018:ffffc90000a08b78 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000a06 RCX: ffffffff81a8333d RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8df46dc0 RBP: ffffc90000a08e30 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff331c0b4 R12: 0000000000002904 R13: 1ffff110170e771a R14: ffffffff8df46dc0 R15: dffffc0000000000 FS: 00007fde583f66c0(0000) GS:ffff888125f37000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 00000000781ea000 CR4: 00000000003526f0 Call Trace: rcu_core+0x6a9/0x1870 kernel/rcu/tree.c:2852 handle_softirqs+0x27d/0x850 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1a b9 40 f6 48 89 df e8 52 30 41 f6 e8 9d 9b 6b f6 fb bf 01 00 00 00 f2 1f 33 f6 65 8b 05 ab a0 20 07 85 c0 74 07 5b e9 d1 4b 00 00 RSP: 0018:ffffc900051bfc60 EFLAGS: 00000286 RAX: 5f147486e0aec900 RBX: ffff888027d3dc80 RCX: 5f147486e0aec900 RDX: 0000000000000000 RSI: ffffffff8d791132 RDI: 0000000000000001 RBP: 0000000000000021 R08: ffffffff8f820377 R09: 1ffffffff1f0406e R10: dffffc0000000000 R11: fffffbfff1f0406f R12: 1ffff11004fa7c23 R13: 0000000000000000 R14: 000000001c000004 R15: ffff888027d3e118 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x11a7/0x1340 kernel/signal.c:3037 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde5a18f749 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:00007fde583f6038 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fde5a3e5fa0 RCX: 00007fde5a18f749 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fde5a213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fde5a3e6038 R14: 00007fde5a3e5fa0 R15: 00007ffd32fd8be8 ---------------- Code disassembly (best guess): 0: 90 nop 1: f3 0f 1e fa endbr64 5: 53 push %rbx 6: 48 89 fb mov %rdi,%rbx 9: 48 83 c7 18 add $0x18,%rdi d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 12: e8 1a b9 40 f6 call 0xf640b931 17: 48 89 df mov %rbx,%rdi 1a: e8 52 30 41 f6 call 0xf6413071 1f: e8 9d 9b 6b f6 call 0xf66b9bc1 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 f2 1f 33 f6 call 0xf6332021 <-- trapping instruction 2f: 65 8b 05 ab a0 20 07 mov %gs:0x720a0ab(%rip),%eax # 0x720a0e1 36: 85 c0 test %eax,%eax 38: 74 07 je 0x41 3a: 5b pop %rbx 3b: e9 d1 4b 00 00 jmp 0x4c11