rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P43/1:b..l P16337/3:b..l P29/4:b..l P12/1:b..l P7829/1:b..l P13/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=96113, q=518 ncpus=2)
task:kworker/u8:1 state:D stack:19000 pid:13 tgid:13 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule_rtlock+0x30/0x70 kernel/sched/core.c:7122
rtlock_slowlock_locked+0x3819/0x4010 kernel/locking/rtmutex.c:1868
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x152/0x2c0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168
local_bh_disable include/linux/bottom_half.h:20 [inline]
spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:831 [inline]
nsim_dev_trap_report_work+0x73b/0xbc0 drivers/net/netdevsim/dev.c:866
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:kworker/u8:17 state:D stack:19032 pid:7829 tgid:7829 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule_rtlock+0x30/0x70 kernel/sched/core.c:7122
rtlock_slowlock_locked+0x3819/0x4010 kernel/locking/rtmutex.c:1868
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x152/0x2c0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168
local_bh_disable include/linux/bottom_half.h:20 [inline]
spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:831 [inline]
nsim_dev_trap_report_work+0x73b/0xbc0 drivers/net/netdevsim/dev.c:866
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:kworker/u8:0 state:D stack:19800 pid:12 tgid:12 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule_rtlock+0x30/0x70 kernel/sched/core.c:7122
rtlock_slowlock_locked+0x3819/0x4010 kernel/locking/rtmutex.c:1868
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x152/0x2c0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168
local_bh_disable include/linux/bottom_half.h:20 [inline]
spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:831 [inline]
nsim_dev_trap_report_work+0x73b/0xbc0 drivers/net/netdevsim/dev.c:866
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:ktimers/1 state:D stack:22280 pid:29 tgid:29 ppid:2 task_flags:0x4208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule_rtlock+0x30/0x70 kernel/sched/core.c:7122
rtlock_slowlock_locked+0x3819/0x4010 kernel/locking/rtmutex.c:1868
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x152/0x2c0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
drm_handle_vblank+0xc1/0x630 drivers/gpu/drm/drm_vblank.c:1930
vkms_vblank_simulate+0xcd/0x320 drivers/gpu/drm/vkms/vkms_crtc.c:30
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x54f/0xd40 kernel/time/hrtimer.c:1825
hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1842
handle_softirqs+0x22f/0x710 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
run_ktimerd+0xcf/0x190 kernel/softirq.c:1043
smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:syz.3.2723 state:D stack:25400 pid:16337 tgid:16335 ppid:12979 task_flags:0x400040 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule_rtlock+0x30/0x70 kernel/sched/core.c:7122
rtlock_slowlock_locked+0x3819/0x4010 kernel/locking/rtmutex.c:1868
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x152/0x2c0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168
local_bh_disable include/linux/bottom_half.h:20 [inline]
spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
hrtimer_cancel_wait_running+0xf2/0x180 kernel/time/hrtimer.c:1460
hrtimer_cancel+0x39/0x60 kernel/time/hrtimer.c:1491
__disable_vblank drivers/gpu/drm/drm_vblank.c:442 [inline]
drm_vblank_disable_and_save+0x1bf/0x380 drivers/gpu/drm/drm_vblank.c:481
drm_crtc_vblank_off+0x22e/0x820 drivers/gpu/drm/drm_vblank.c:1364
crtc_disable drivers/gpu/drm/drm_atomic_helper.c:1258 [inline]
disable_outputs drivers/gpu/drm/drm_atomic_helper.c:1340 [inline]
drm_atomic_helper_commit_modeset_disables+0xc89/0x2010 drivers/gpu/drm/drm_atomic_helper.c:1524
vkms_atomic_commit_tail+0x51/0x210 drivers/gpu/drm/vkms/vkms_drv.c:61
commit_tail+0x284/0x3a0 drivers/gpu/drm/drm_atomic_helper.c:1986
drm_atomic_helper_commit+0xa6b/0xb10 drivers/gpu/drm/drm_atomic_helper.c:2226
drm_atomic_commit+0x262/0x2c0 drivers/gpu/drm/drm_atomic.c:1577
drm_atomic_helper_set_config+0xe2/0x160 drivers/gpu/drm/drm_atomic_helper.c:3426
drm_mode_setcrtc+0x9a7/0x1c50 drivers/gpu/drm/drm_crtc.c:869
drm_ioctl_kernel+0x2cf/0x3a0 drivers/gpu/drm/drm_ioctl.c:796
drm_ioctl+0x685/0xb20 drivers/gpu/drm/drm_ioctl.c:893
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:598 [inline]
__se_sys_ioctl+0xff/0x170 fs/ioctl.c:584
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff2ef72eec9
RSP: 002b:00007ff2ed96d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff2ef986090 RCX: 00007ff2ef72eec9
RDX: 0000200000000400 RSI: 00000000c06864a2 RDI: 0000000000000003
RBP: 00007ff2ef7b1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff2ef986128 R14: 00007ff2ef986090 R15: 00007ffed5026e68
task:kworker/u8:2 state:D stack:18952 pid:43 tgid:43 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule_rtlock+0x30/0x70 kernel/sched/core.c:7122
rtlock_slowlock_locked+0x3819/0x4010 kernel/locking/rtmutex.c:1868
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x152/0x2c0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168
local_bh_disable include/linux/bottom_half.h:20 [inline]
spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:831 [inline]
nsim_dev_trap_report_work+0x73b/0xbc0 drivers/net/netdevsim/dev.c:866
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread timer wakeup didn't happen for 10495 jiffies! g96113 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=58189
rcu: rcu_preempt kthread starved for 10496 jiffies! g96113 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:25840 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 13 b3 03 00 cc cc cc 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 13 26 11 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900001d7de0 EFLAGS: 000002c6
RAX: 77bcc02444eaf900 RBX: ffffffff81955f48 RCX: 77bcc02444eaf900
RDX: 0000000000000001 RSI: ffffffff8d03ad79 RDI: ffffffff8b621680
RBP: ffffc900001d7f20 R08: ffff8880b893341b R09: 1ffff11017126683
R10: dffffc0000000000 R11: ffffed1017126684 R12: ffffffff8f1d6330
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100385cb28
FS: 0000000000000000(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055bbc0186fa0 CR3: 000000003a646000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147