rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10500 ticks this GP) idle=df9/1/0x4000000000000000 softirq=69152/69152 fqs=5218 (t=10502 jiffies g=129325 q=1760) NMI backtrace for cpu 1 CPU: 1 PID: 29940 Comm: vhost-29939 Not tainted 5.15.0-rc7-next-20211026-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:__sanitizer_cov_trace_pc+0x4c/0x60 kernel/kcov.c:205 Code: 0e 85 c9 74 35 8b 82 ac 15 00 00 85 c0 74 2b 8b 82 88 15 00 00 83 f8 02 75 20 48 8b 8a 90 15 00 00 8b 92 8c 15 00 00 48 8b 01 <48> 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 c3 0f 1f 00 41 55 RSP: 0018:ffffc90017417b20 EFLAGS: 00000246 RAX: 000000000003ffff RBX: 0000000000000010 RCX: ffffc90017565000 RDX: 0000000000040000 RSI: ffffffff86dcaa1c RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000010 R09: ffff88803d3101fb R10: ffffffff86dcaa0b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 iotlb_access_ok+0x1bc/0x3e0 drivers/vhost/vhost.c:1336 vq_meta_prefetch+0xbc/0x280 drivers/vhost/vhost.c:1366 handle_rx+0x145/0x1b40 drivers/vhost/net.c:1140 vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 85 c9 test %ecx,%ecx 2: 74 35 je 0x39 4: 8b 82 ac 15 00 00 mov 0x15ac(%rdx),%eax a: 85 c0 test %eax,%eax c: 74 2b je 0x39 e: 8b 82 88 15 00 00 mov 0x1588(%rdx),%eax 14: 83 f8 02 cmp $0x2,%eax 17: 75 20 jne 0x39 19: 48 8b 8a 90 15 00 00 mov 0x1590(%rdx),%rcx 20: 8b 92 8c 15 00 00 mov 0x158c(%rdx),%edx 26: 48 8b 01 mov (%rcx),%rax * 29: 48 83 c0 01 add $0x1,%rax <-- trapping instruction 2d: 48 39 c2 cmp %rax,%rdx 30: 76 07 jbe 0x39 32: 48 89 34 c1 mov %rsi,(%rcx,%rax,8) 36: 48 89 01 mov %rax,(%rcx) 39: c3 retq 3a: 0f 1f 00 nopl (%rax) 3d: 41 55 push %r13