rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29/2:b..l P6185/2:b..l P5170/1:b..l P5809/4:b..l P16/1:b..l P6193/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=12181, q=490 ncpus=2)
task:syz.2.67 state:R running task stack:24112 pid:6193 tgid:6192 ppid:5803 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 ab 4f 6e f6 cc
RSP: 0018:ffffc90008397418 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff888028b46000 RCX: ffff888059791e00
RDX: 0000000000000002 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900083974a0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff9400025c1c7 R12: ffffc900083975c0
R13: 00000000000007d7 R14: 1ffff92001072e84 R15: dffffc0000000000
rcu_read_lock_held_common kernel/rcu/update.c:105 [inline]
rcu_read_lock_sched_held+0x60/0x100 kernel/rcu/update.c:124
task_css include/linux/cgroup.h:459 [inline]
blkcg_css+0x71/0x1d0 block/blk-cgroup.c:110
blk_cgroup_congested+0xbc/0x210 block/blk-cgroup.c:2238
__folio_throttle_swaprate+0x67/0x190 mm/swapfile.c:4065
folio_throttle_swaprate include/linux/swap.h:617 [inline]
shmem_add_to_page_cache+0x6f1/0xbc0 mm/shmem.c:882
shmem_alloc_and_add_folio mm/shmem.c:1936 [inline]
shmem_get_folio_gfp+0x7d2/0x1a70 mm/shmem.c:2533
shmem_fault+0x170/0x380 mm/shmem.c:2734
__do_fault+0x138/0x390 mm/memory.c:5280
do_read_fault mm/memory.c:5698 [inline]
do_fault mm/memory.c:5832 [inline]
do_pte_missing mm/memory.c:4361 [inline]
handle_pte_fault mm/memory.c:6177 [inline]
__handle_mm_fault mm/memory.c:6318 [inline]
handle_mm_fault+0x23c6/0x3400 mm/memory.c:6487
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x1685/0x2860 mm/gup.c:1428
populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860
__mm_populate+0x24c/0x380 mm/gup.c:1963
mm_populate include/linux/mm.h:3471 [inline]
vm_mmap_pgoff+0x38a/0x4d0 mm/util.c:586
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb6024f6c9
RSP: 002b:00007feb5e4ae038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007feb604a5fa0 RCX: 00007feb6024f6c9
RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007feb602d1f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feb604a6038 R14: 00007feb604a5fa0 R15: 00007ffc5f010688
task:ktimers/0 state:R running task stack:22808 pid:16 tgid:16 ppid:2 task_flags:0x4208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 9b 81 06 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900001579a0 EFLAGS: 00000206
RAX: 751a2bd19ec6f300 RBX: 0000000000000000 RCX: 751a2bd19ec6f300
RDX: 0000000000000000 RSI: ffffffff8cf64b05 RDI: ffffffff8b3ddd60
RBP: ffffffff81ac8b4c R08: 0000000000000000 R09: ffffffff81ac8b4c
R10: dffffc0000000000 R11: ffffffff81ac8ad0 R12: 0000000000000000
R13: ffff8880b8827e78 R14: 0000000000000001 R15: 0000000000000246
rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
spin_lock include/linux/spinlock_rt.h:44 [inline]
hrtimer_cpu_base_lock_expiry kernel/time/hrtimer.c:1376 [inline]
hrtimer_run_softirq+0x7c/0x2e0 kernel/time/hrtimer.c:1854
handle_softirqs+0x22f/0x710 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:syz-executor state:R running task stack:20904 pid:5809 tgid:5809 ppid:5798 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
rcu_read_unlock_sched include/linux/rcupdate.h:981 [inline]
pfn_valid+0x402/0x490 include/linux/mmzone.h:2197
page_table_check_set+0x25/0x730 mm/page_table_check.c:105
page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
set_ptes include/linux/pgtable.h:292 [inline]
__copy_present_ptes mm/memory.c:1100 [inline]
copy_present_ptes mm/memory.c:1179 [inline]
copy_pte_range mm/memory.c:1302 [inline]
copy_pmd_range+0x4790/0x7950 mm/memory.c:1389
copy_pud_range mm/memory.c:1426 [inline]
copy_p4d_range mm/memory.c:1450 [inline]
copy_page_range+0xaff/0x1170 mm/memory.c:1538
dup_mmap+0xf5b/0x1ae0 mm/mmap.c:1834
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1704/0x3ae0 kernel/fork.c:2181
kernel_clone+0x224/0x7c0 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbfdbe75e13
RSP: 002b:00007ffd2680e088 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbfdbe75e13
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000555572d447d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000002700d R15: 00007ffd2680e220
task:udevd state:R running task stack:24072 pid:5170 tgid:5170 ppid:1 task_flags:0x400140 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_is_held_type+0x9/0x190 kernel/locking/lockdep.c:5925
Code: eb b5 e8 1a fc ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 <41> 55 41 54 53 48 83 ec 10 65 48 8b 05 16 fb e1 06 48 89 44 24 08
RSP: 0018:ffffc90004027800 EFLAGS: 00000202
RAX: 1ffffffff1ab5f01 RBX: ffffffff825625ac RCX: 99caf0a0243c7100
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8d5aa840
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffff888140447de0 R11: ffffffff82563920 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888024236d20 R15: ffff88814331a870
kernfs_root+0xf6/0x230 fs/kernfs/kernfs-internal.h:76
kernfs_iop_permission+0x6c/0x430 fs/kernfs/inode.c:287
do_inode_permission fs/namei.c:526 [inline]
inode_permission+0x285/0x470 fs/namei.c:593
may_lookup fs/namei.c:1858 [inline]
link_path_walk+0x232/0xea0 fs/namei.c:2467
path_lookupat+0x97/0x430 fs/namei.c:2675
filename_lookup+0x212/0x570 fs/namei.c:2705
vfs_statx+0xf8/0x550 fs/stat.c:353
vfs_fstatat+0x118/0x170 fs/stat.c:375
__do_sys_newfstatat fs/stat.c:542 [inline]
__se_sys_newfstatat fs/stat.c:536 [inline]
__x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f856938eb0a
RSP: 002b:00007ffed6b10048 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffed6b104e0 RCX: 00007f856938eb0a
RDX: 00007ffed6b10050 RSI: 00007ffed6b104e0 RDI: 00000000ffffff9c
RBP: 0000557be9889910 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffed6b100e0
R13: 0000000000000100 R14: 0000557be6370be0 R15: 00007ffed6b10b60
task:syz.3.62 state:R running task stack:26632 pid:6185 tgid:6171 ppid:5815 task_flags:0x40044c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
class_preempt_destructor include/linux/preempt.h:470 [inline]
raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:99 [inline]
rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x2fb/0x3e0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__folio_batch_add_and_move+0x284/0xa90 mm/swap.c:-1
folio_mark_accessed+0x36c/0x4a0 mm/swap.c:480
zap_present_folio_ptes mm/memory.c:1636 [inline]
zap_present_ptes mm/memory.c:1709 [inline]
do_zap_pte_range mm/memory.c:1810 [inline]
zap_pte_range mm/memory.c:1854 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x18fa/0x3c10 mm/memory.c:2017
unmap_single_vma mm/memory.c:2060 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2104
exit_mmap+0x240/0xb40 mm/mmap.c:1280
__mmput+0xcb/0x3d0 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:954
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x125d/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f10af7ff6c9
RSP: 002b:00007f10ada3d038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f10afa56090 RCX: 00007f10af7ff6c9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f10af881f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f10afa56128 R14: 00007f10afa56090 R15: 00007ffd6e6682d8
task:ktimers/1 state:R running task stack:22352 pid:29 tgid:29 ppid:2 task_flags:0x4208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline]
rt_mutex_slowunlock+0x493/0x8a0 kernel/locking/rtmutex.c:1454
spin_unlock_irqrestore include/linux/spinlock_rt.h:122 [inline]
class_spinlock_irqsave_destructor include/linux/spinlock.h:585 [inline]
snd_seq_check_queue+0x17d/0x560 sound/core/seq/seq_queue.c:240
snd_timer_process_callbacks+0x225/0x2f0 sound/core/timer.c:785
snd_timer_interrupt+0xecb/0x10c0 sound/core/timer.c:901
snd_hrtimer_callback+0x213/0x3a0 sound/core/hrtimer.c:51
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x552/0xd40 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1858
handle_softirqs+0x22f/0x710 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread timer wakeup didn't happen for 10204 jiffies! g12181 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=6035
rcu: rcu_preempt kthread starved for 10205 jiffies! g12181 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:27352 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
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+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc 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 03 c8 27 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:ffffffff8d207d80 EFLAGS: 000002c2
RAX: 93c3a96d89fd4d00 RBX: ffffffff81954cf7 RCX: 93c3a96d89fd4d00
RDX: 0000000000000001 RSI: ffffffff8cd8de17 RDI: ffffffff8b3ddd60
RBP: ffffffff8d207ea8 R08: ffff8880b88334db R09: 1ffff1101710669b
R10: dffffc0000000000 R11: ffffed101710669c R12: ffffffff8ed63670
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1a60640
FS: 0000000000000000(0000) GS:ffff888126df9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdee9ccd0a3 CR3: 0000000038b2a000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3ae/0x410 init/main.c:1111
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147