------------[ cut here ]------------ WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049, CPU#0: syz.3.957/9433 Modules linked in: CPU: 0 UID: 0 PID: 9433 Comm: syz.3.957 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049 Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 c0 52 c2 9a e8 b0 3a 85 00 b8 01 00 00 00 87 05 d5 c4 1e 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 74 e5 88 90 48 81 fd 80 46 3d 8e 74 5a 48 b8 00 RSP: 0018:ffffc90000007df0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81a38de0 RDX: fffffbfff3584a58 RSI: 0000000000000004 RDI: ffffffff9ac252c0 RBP: ffffffff8e3d4680 R08: 0000000000000001 R09: fffffbfff3584a58 R10: 0000000000000003 R11: ffff88803288d4b0 R12: 1ffffffff1c02250 R13: 0000000000000246 R14: ffffffff8e3d4680 R15: ffff8880b843bc52 FS: 00007f555314e6c0(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b300f8ff8 CR3: 0000000079903000 CR4: 00000000003526f0 Call Trace: rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1012 [inline] rcu_core+0x4cf/0x15f0 kernel/rcu/tree.c:2852 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 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 8b 74 24 08 48 89 fb 48 83 c7 18 e8 7a fe 1e f6 48 89 df e8 32 51 1f f6 e8 ad 12 4c f6 fb bf 01 00 00 00 42 54 0f f6 65 8b 05 9b b9 37 08 85 c0 74 06 5b e9 01 4d 00 00 RSP: 0018:ffffc90003507ca0 EFLAGS: 00000206 RAX: 000000000c559bed RBX: ffff88807aa3ca00 RCX: ffffffff81c7083f RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: 0000000000000001 RBP: ffff88807aa3cc00 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9088b4d7 R11: ffff88803288d4b0 R12: 0000000000000000 R13: 0000000000000011 R14: 0000000000000200 R15: ffff88807aa3ca00 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1e6a/0x26d0 kernel/signal.c:3037 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 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+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f555238f749 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:00007f555314e0e8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00007f55525e6188 RCX: 00007f555238f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f55525e6188 RBP: 00007f55525e6180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f55525e6218 R14: 00007ffe1bbf7610 R15: 00007ffe1bbf76f8 ---------------- Code disassembly (best guess): 0: 90 nop 1: f3 0f 1e fa endbr64 5: 53 push %rbx 6: 48 8b 74 24 08 mov 0x8(%rsp),%rsi b: 48 89 fb mov %rdi,%rbx e: 48 83 c7 18 add $0x18,%rdi 12: e8 7a fe 1e f6 call 0xf61efe91 17: 48 89 df mov %rbx,%rdi 1a: e8 32 51 1f f6 call 0xf61f5151 1f: e8 ad 12 4c f6 call 0xf64c12d1 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 42 54 0f f6 call 0xf60f5471 <-- trapping instruction 2f: 65 8b 05 9b b9 37 08 mov %gs:0x837b99b(%rip),%eax # 0x837b9d1 36: 85 c0 test %eax,%eax 38: 74 06 je 0x40 3a: 5b pop %rbx 3b: e9 01 4d 00 00 jmp 0x4d41