rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (1 GPs behind) idle=7ebc/1/0x4000000000000000 softirq=27361/27364 fqs=269
rcu: (t=10500 jiffies g=20109 q=106 ncpus=2)
rcu: rcu_preempt kthread starved for 9052 jiffies! g20109 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28384 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline]
RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline]
RIP: 0010:native_apic_msr_write arch/x86/include/asm/apic.h:212 [inline]
RIP: 0010:native_apic_msr_write+0x28/0x40 arch/x86/include/asm/apic.h:206
Code: 90 90 f3 0f 1e fa 8d 87 30 ff ff ff 83 e0 ef 74 20 89 f8 83 e0 ef 83 f8 20 74 16 c1 ef 04 31 d2 89 f0 8d 8f 00 08 00 00 0f 30 <66> 90 e9 01 bd f8 09 e9 fc bc f8 09 89 f6 31 d2 89 cf e9 71 0b 6f
RSP: 0018:ffffc90000007ec0 EFLAGS: 00000046
RAX: 000000000007aabe RBX: ffff8880b8423a00 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000007aabe RDI: 0000000000000038
RBP: 000000000007aabe R08: 0000000000000005 R09: 000000000000003f
R10: 0000000000000020 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000020 R15: ffff8880b8427c80
FS: 0000000000000000(0000) GS:ffff888124a0a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff687dbfcc8 CR3: 000000007499f000 CR4: 00000000003526f0
Call Trace:
apic_write arch/x86/include/asm/apic.h:409 [inline]
lapic_next_event+0x10/0x20 arch/x86/kernel/apic/apic.c:416
clockevents_program_event+0x272/0x380 kernel/time/clockevents.c:334
tick_program_event+0xa9/0x140 kernel/time/tick-oneshot.c:44
hrtimer_interrupt+0x3e9/0x8e0 kernel/time/hrtimer.c:1916
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 07 6d 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 d5 29 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 0000000001093b2b RBX: 0000000000000000 RCX: ffffffff8b6052a9
RDX: 0000000000000000 RSI: ffffffff8da2a287 RDI: ffffffff8bf06e40
RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655
R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e097a00 R14: ffffffff9081f6d0 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x38d/0x500 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3f6/0x4e0 init/main.c:1111
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148
CPU: 1 UID: 0 PID: 1300 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline]
RIP: 0010:raw_atomic_try_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2130 [inline]
RIP: 0010:raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2431 [inline]
RIP: 0010:raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline]
RIP: 0010:atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline]
RIP: 0010:uart_port_ref drivers/tty/serial/serial_core.c:67 [inline]
RIP: 0010:uart_port_ref_lock drivers/tty/serial/serial_core.c:80 [inline]
RIP: 0010:uart_write_room+0xb2/0x940 drivers/tty/serial/serial_core.c:645
Code: e8 03 51 96 fc 31 ff 44 89 e6 e8 39 4c 96 fc 45 85 e4 0f 84 cf 02 00 00 e8 eb 50 96 fc 41 8d 54 24 01 44 89 e0 f0 0f b1 55 00 <41> 0f 94 c6 31 ff 41 89 c5 44 89 f6 e8 ad 4b 96 fc 45 84 f6 0f 84
RSP: 0018:ffffc9000463f970 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff888141f80be8 RCX: ffffffff8526ba97
RDX: 0000000000000002 RSI: ffffffff8526baa5 RDI: 0000000000000005
RBP: ffff888141f80f84 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001
R13: ffff88804caa8d80 R14: 0000000000000020 R15: ffff88804caa8000
FS: 0000000000000000(0000) GS:ffff888124b0a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c4462b7 CR3: 00000000442ce000 CR4: 00000000003526f0
Call Trace:
tty_write_room+0x66/0x90 drivers/tty/tty_ioctl.c:69
handle_tx+0x14f/0x630 drivers/net/caif/caif_serial.c:212
__netdev_start_xmit include/linux/netdevice.h:5248 [inline]
netdev_start_xmit include/linux/netdevice.h:5257 [inline]
xmit_one net/core/dev.c:3845 [inline]
dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3861
__dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4763
dev_queue_xmit include/linux/netdevice.h:3365 [inline]
tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
kthread+0x1e4/0x3e0 drivers/block/aoe/aoecmd.c:1241
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245