syzbot

sched: DL replenish lagged too much
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7854/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=23253, q=3472 ncpus=2)
task:syz.1.486       state:R  running task     stack:26744 pid:7854  tgid:7852  ppid:5809   task_flags:0x40054c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x60e0 kernel/sched/core.c:6907
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7234
 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline]
RIP: 0010:unwind_next_frame+0x156b/0x1ea0 arch/x86/kernel/unwind_orc.c:680
Code: 00 0f 85 cf 03 00 00 49 8d 7d 08 49 8b 5d 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 e1 06 00 00 <49> 8d 7d 10 49 8b 6d 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48
RSP: 0018:ffffc90003c7f280 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc90003c7f970 RCX: ffffffff91c07428
RDX: 1ffff9200078fe5f RSI: ffffc90003c7f958 RDI: ffffc90003c7f2f8
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000049f95 R12: ffffc90003c7f340
R13: ffffc90003c7f2f0 R14: ffffc90003c7f970 R15: ffffc90003c7f324
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x162/0x1e0 mm/page_owner.c:165
 __reset_page_owner+0x84/0x190 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:406
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5219 [inline]
 __kmalloc_noprof+0x301/0x850 mm/slub.c:5231
 kmalloc_noprof include/linux/slab.h:966 [inline]
 kmalloc_array_noprof include/linux/slab.h:1113 [inline]
 drm_atomic_state_init+0xec/0x540 drivers/gpu/drm/drm_atomic.c:135
 drm_atomic_state_alloc drivers/gpu/drm/drm_atomic.c:182 [inline]
 drm_atomic_state_alloc+0xd3/0x120 drivers/gpu/drm/drm_atomic.c:172
 drm_client_modeset_commit_atomic+0xcc/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1044
 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1206
 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1232
 __drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x137/0x160 drivers/gpu/drm/drm_fb_helper.c:137
 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:125 [inline]
 drm_fb_helper_restore_fbdev_mode_unlocked+0x93/0xc0 drivers/gpu/drm/drm_fb_helper.c:168
 drm_fbdev_client_restore+0x1b/0x30 drivers/gpu/drm/clients/drm_fbdev_client.c:45
 drm_client_dev_restore+0x205/0x2a0 drivers/gpu/drm/drm_client_event.c:118
 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
 drm_release+0x2c6/0x360 drivers/gpu/drm/drm_file.c:441
 __fput+0x3ff/0xb40 fs/file_table.c:469
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x829/0x2aa0 kernel/exit.c:971
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f31d759c629
RSP: 002b:00007f31d57f60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f31d7815fa8 RCX: 00007f31d759c629
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f31d7815fa8
RBP: 00007f31d7815fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f31d7816038 R14: 00007ffdc4af2070 R15: 00007ffdc4af2158
 </TASK>
rcu: rcu_preempt kthread starved for 1461 jiffies! g23253 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:28584 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x60e0 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7004
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 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: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: c8 82 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 fc 1b 00 fb f4 <e9> bc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000242
RAX: 0000000001463d89 RBX: ffff88801e6b2480 RCX: ffffffff8b8f8c75
RDX: 0000000000000000 RSI: ffffffff8de71f10 RDI: ffffffff8c1aefa0
RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed10170a6795
R10: ffff8880b8533cab R11: 0000000000000000 R12: ffffed1003cd6490
R13: 0000000000000001 R14: ffffffff90d96410 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124447000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d0471ca010 CR3: 0000000020b94000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x35b/0x4b0 kernel/sched/idle.c:332
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>