rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10499 ticks this GP) idle=91d/1/0x4000000000000000 softirq=9714/9714 fqs=3884 (t=10500 jiffies g=11093 q=47) NMI backtrace for cpu 0 CPU: 0 PID: 6487 Comm: syz-executor141 Not tainted 5.15.0-rc7-next-20211029-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3922 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2620 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:104 [inline] RIP: 0010:do_raw_spin_unlock+0x101/0x230 kernel/locking/spinlock_debug.c:140 Code: 8e fc 00 00 00 65 8b 05 e5 c5 a4 7e 39 45 08 0f 85 b5 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 <0f> 85 f5 00 00 00 4c 89 e2 48 c7 45 10 ff ff ff ff 48 b8 00 00 00 RSP: 0018:ffffc90002a8fcc8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff88801a315950 RCX: ffffffff815d4f10 RDX: 1ffff1100449ce7a RSI: 0000000000000004 RDI: ffff8880224e73c0 RBP: ffff8880224e73c0 R08: 0000000000000000 R09: ffff8880224e73c3 R10: ffffed100449ce78 R11: 0000000000000000 R12: ffff8880224e73c8 R13: ffff8880224e73d0 R14: ffff88801a315918 R15: ffff88801a3158c0 __raw_spin_unlock include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock+0x1a/0x40 kernel/locking/spinlock.c:186 tctx_task_work+0x1b3/0x630 fs/io_uring.c:2207 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xc14/0x2b40 kernel/exit.c:832 do_group_exit+0x125/0x310 kernel/exit.c:929 __do_sys_exit_group kernel/exit.c:940 [inline] __se_sys_exit_group kernel/exit.c:938 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:938 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe6950481a9 Code: Unable to access opcode bytes at RIP 0x7fe69504817f. RSP: 002b:00007ffc42a91cb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fe6950bc330 RCX: 00007fe6950481a9 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 00000000f5ffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe6950bc330 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 ---------------- Code disassembly (best guess): 0: 8e fc mov %esp,%? 2: 00 00 add %al,(%rax) 4: 00 65 8b add %ah,-0x75(%rbp) 7: 05 e5 c5 a4 7e add $0x7ea4c5e5,%eax c: 39 45 08 cmp %eax,0x8(%rbp) f: 0f 85 b5 00 00 00 jne 0xca 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 4c 89 ea mov %r13,%rdx 22: 48 c1 ea 03 shr $0x3,%rdx 26: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) * 2a: 0f 85 f5 00 00 00 jne 0x125 <-- trapping instruction 30: 4c 89 e2 mov %r12,%rdx 33: 48 c7 45 10 ff ff ff movq $0xffffffffffffffff,0x10(%rbp) 3a: ff 3b: 48 rex.W 3c: b8 .byte 0xb8 3d: 00 00 add %al,(%rax)