rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5860/2:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=11197, q=2549 ncpus=2)
task:kworker/u8:19   state:D stack:26704 pid:5860  tgid:5860  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_unbound nsim_dev_trap_report_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule_rtlock+0x30/0x70 kernel/sched/core.c:7390
 rtlock_slowlock_locked+0x35c5/0x3c20 kernel/locking/rtmutex.c:1895
 rtlock_slowlock kernel/locking/rtmutex.c:1922 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:45 [inline]
 tasklet_lock_callback kernel/softirq.c:877 [inline]
 tasklet_action_common+0xc5/0x600 kernel/softirq.c:927
 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 spin_unlock_bh include/linux/spinlock_rt.h:116 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline]
 nsim_dev_trap_report_work+0x871/0xcb0 drivers/net/netdevsim/dev.c:922
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread starved for 359 jiffies! g11197 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:25616 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7234
 preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7506
 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
 class_preempt_notrace_destructor include/linux/preempt.h:469 [inline]
 trace_event_raw_event_lock+0x23f/0x280 include/trace/events/lock.h:49
 __do_trace_lock_release include/trace/events/lock.h:68 [inline]
 trace_lock_release include/trace/events/lock.h:68 [inline]
 lock_release+0x38e/0x3c0 kernel/locking/lockdep.c:5879
 rcu_lock_release include/linux/rcupdate.h:310 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
 unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4584 [inline]
 slab_alloc_node mm/slub.c:4917 [inline]
 kmem_cache_alloc_noprof+0x355/0x650 mm/slub.c:4931
 kmem_alloc_batch lib/debugobjects.c:371 [inline]
 fill_pool+0x165/0x610 lib/debugobjects.c:420
 debug_objects_fill_pool+0x63/0x80 lib/debugobjects.c:780
 debug_object_assert_init+0x65/0x310 lib/debugobjects.c:1066
 debug_timer_assert_init kernel/time/timer.c:803 [inline]
 debug_assert_init kernel/time/timer.c:848 [inline]
 __try_to_del_timer_sync kernel/time/timer.c:1457 [inline]
 __timer_delete_sync+0x247/0x600 kernel/time/timer.c:1621
 schedule_timeout+0x15a/0x2c0 kernel/time/sleep_timeout.c:100
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5867 Comm: kworker/u8:21 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:finish_task_switch+0x417/0xc60 kernel/sched/core.c:5361
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 93 ca b1 09 e8 fe bd 38 00 fb 4c 8b 65 c8 <49> 8d bc 24 e0 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900061b6000 EFLAGS: 00000206
RAX: 0000000000004f21 RBX: ffff8880b863c6e0 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8d881224 RDI: ffffffff8bca5980
RBP: ffffc900061b6050 R08: ffffffff8faf4c37 R09: 1ffffffff1f5e986
R10: dffffc0000000000 R11: fffffbfff1f5e987 R12: ffff88803040dd00
R13: ffff8880b863c6b8 R14: dffffc0000000000 R15: 1ffff110170c78dc
FS:  0000000000000000(0000) GS:ffff888125c46000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564067ad4000 CR3: 000000003b63a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5513 [inline]
 __schedule+0x16e4/0x5500 kernel/sched/core.c:7234
 preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7506
 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
 class_preempt_notrace_destructor include/linux/preempt.h:469 [inline]
 trace_event_raw_event_lock+0x23f/0x280 include/trace/events/lock.h:49
 __do_trace_lock_release include/trace/events/lock.h:68 [inline]
 trace_lock_release include/trace/events/lock.h:68 [inline]
 lock_release+0x38e/0x3c0 kernel/locking/lockdep.c:5879
 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80
 spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline]
 __slab_free+0x20a/0x2a0 mm/slub.c:-1
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4584 [inline]
 slab_alloc_node mm/slub.c:4917 [inline]
 kmem_cache_alloc_noprof+0x355/0x650 mm/slub.c:4931
 ext4_mb_new_blocks+0x543/0x4540 fs/ext4/mballoc.c:6290
 ext4_ext_map_blocks+0x1534/0x5850 fs/ext4/extents.c:4461
 ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:631
 ext4_map_blocks+0x7e4/0x1240 fs/ext4/inode.c:824
 mpage_map_one_extent fs/ext4/inode.c:2397 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2491 [inline]
 ext4_do_writepages+0x23d6/0x47a0 fs/ext4/inode.c:2949
 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3043
 do_writepages+0x338/0x560 mm/page-writeback.c:2571
 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787
 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2079
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2155
 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2266
 wb_check_old_data_flush fs/fs-writeback.c:2370 [inline]
 wb_do_writeback fs/fs-writeback.c:2449 [inline]
 wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2477
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>