rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (10500 ticks this GP) idle=a33/1/0x4000000000000000 softirq=64978/64978 fqs=0
(t=10500 jiffies g=104989 q=2042)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g104989 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=59428
rcu: rcu_preempt kthread starved for 10500 jiffies! g104989 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:I stack:26576 pid: 14 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:4972 [inline]
__schedule+0xb72/0x1460 kernel/sched/core.c:6253
schedule+0x12b/0x1f0 kernel/sched/core.c:6326
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1881
rcu_gp_fqs_loop+0x1fd/0x770 kernel/rcu/tree.c:1955
rcu_gp_kthread+0xa5/0x350 kernel/rcu/tree.c:2128
kthread+0x468/0x490 kernel/kthread.c:327
ret_from_fork+0x1f/0x30
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 1230 Comm: aoe_tx0 Tainted: G S 5.16.0-rc4-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_check_gp_kthread_starvation+0x1ff/0x270 kernel/rcu/tree_stall.h:481
print_cpu_stall kernel/rcu/tree_stall.h:625 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]
rcu_pending kernel/rcu/tree.c:3878 [inline]
rcu_sched_clock_irq+0x1e2e/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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 52 75 bb f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 77 3f 45 f7 65 8b 05 58 7a ed 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0018:ffffc9000518f8c0 EFLAGS: 00000206
RAX: 7f2f88f6c2312a00 RBX: 1ffff92000a31f1c RCX: ffffffff81667f91
RDX: dffffc0000000000 RSI: 0000000000000202 RDI: 0000000000000001
RBP: ffffc9000518f958 R08: dffffc0000000000 R09: fffffbfff1ff3604
R10: fffffbfff1ff3604 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92000a31f18 R14: ffffc9000518f8e0 R15: 0000000000000246
spin_unlock_irqrestore include/linux/spinlock.h:404 [inline]
uart_write+0x3b9/0x920 drivers/tty/serial/serial_core.c:580
handle_tx+0x249/0x630 drivers/net/caif/caif_serial.c:236
__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
NMI backtrace for cpu 0
CPU: 0 PID: 1230 Comm: aoe_tx0 Tainted: G S 5.16.0-rc4-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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 52 75 bb f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 77 3f 45 f7 65 8b 05 58 7a ed 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0018:ffffc9000518f8c0 EFLAGS: 00000206
RAX: 7f2f88f6c2312a00 RBX: 1ffff92000a31f1c RCX: ffffffff81667f91
RDX: dffffc0000000000 RSI: 0000000000000202 RDI: 0000000000000001
RBP: ffffc9000518f958 R08: dffffc0000000000 R09: fffffbfff1ff3604
R10: fffffbfff1ff3604 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92000a31f18 R14: ffffc9000518f8e0 R15: 0000000000000246
spin_unlock_irqrestore include/linux/spinlock.h:404 [inline]
uart_write+0x3b9/0x920 drivers/tty/serial/serial_core.c:580
handle_tx+0x249/0x630 drivers/net/caif/caif_serial.c:236
__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: 9c pushfq
1: 8f 44 24 20 popq 0x20(%rsp)
5: 42 80 3c 23 00 cmpb $0x0,(%rbx,%r12,1)
a: 74 08 je 0x14
c: 4c 89 f7 mov %r14,%rdi
f: e8 52 75 bb f7 callq 0xf7bb7566
14: f6 44 24 21 02 testb $0x2,0x21(%rsp)
19: 75 4e jne 0x69
1b: 41 f7 c7 00 02 00 00 test $0x200,%r15d
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 77 3f 45 f7 callq 0xf7453fa6 <-- trapping instruction
2f: 65 8b 05 58 7a ed 75 mov %gs:0x75ed7a58(%rip),%eax # 0x75ed7a8e
36: 85 c0 test %eax,%eax
38: 74 3f je 0x79
3a: 48 rex.W
3b: c7 .byte 0xc7
3c: 04 24 add $0x24,%al
3e: 0e (bad)
3f: 36 ss