rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=73b/1/0x4000000000000000 softirq=86173/86174 fqs=5100 (t=10500 jiffies g=115309 q=1341) NMI backtrace for cpu 0 CPU: 0 PID: 1228 Comm: aoe_tx0 Not tainted 5.16.0-rc7-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+0x1dc/0x2d8 lib/dump_stack.c:106 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x22d/0x390 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq+0x1e33/0x2bc0 kernel/rcu/tree.c:2597 update_process_times+0x197/0x200 kernel/time/timer.c:1785 tick_sched_handle kernel/time/tick-sched.c:226 [inline] tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:handle_tx+0x387/0x630 drivers/net/caif/caif_serial.c:250 Code: e8 6e 69 84 fc 48 01 5d 00 31 ff 89 de e8 b1 fe 39 fc 85 db 0f 88 62 01 00 00 4c 89 ff 44 89 ee e8 3e c0 c8 02 48 8b 44 24 58 <42> 0f b6 04 30 84 c0 0f 85 a2 00 00 00 48 8b 44 24 10 8b 18 31 ff RSP: 0018:ffffc9000569fa08 EFLAGS: 00000282 RAX: 1ffff1100fb102ae RBX: 0000000000000000 RCX: ffff88801d9c5700 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffff8880768ae140 R08: ffffffff8813443e R09: ffffed1028e0f1f1 R10: ffffed1028e0f1f1 R11: 0000000000000000 R12: ffff8880768aed08 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88807d881500 __netdev_start_xmit include/linux/netdevice.h:4994 [inline] netdev_start_xmit include/linux/netdevice.h:5008 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x20b/0x450 net/core/dev.c:3606 __dev_queue_xmit+0x1adc/0x35c0 net/core/dev.c:4229 tx+0x6f/0x110 drivers/block/aoe/aoenet.c:63 kthread+0x241/0x450 drivers/block/aoe/aoecmd.c:1230 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 ---------------- Code disassembly (best guess): 0: e8 6e 69 84 fc callq 0xfc846973 5: 48 01 5d 00 add %rbx,0x0(%rbp) 9: 31 ff xor %edi,%edi b: 89 de mov %ebx,%esi d: e8 b1 fe 39 fc callq 0xfc39fec3 12: 85 db test %ebx,%ebx 14: 0f 88 62 01 00 00 js 0x17c 1a: 4c 89 ff mov %r15,%rdi 1d: 44 89 ee mov %r13d,%esi 20: e8 3e c0 c8 02 callq 0x2c8c063 25: 48 8b 44 24 58 mov 0x58(%rsp),%rax * 2a: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 a2 00 00 00 jne 0xd9 37: 48 8b 44 24 10 mov 0x10(%rsp),%rax 3c: 8b 18 mov (%rax),%ebx 3e: 31 ff xor %edi,%edi