rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4971/1:b..l P6413/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=21621, q=1065 ncpus=1)
task:syz.0.138 state:R running task stack:25968 pid:6413 tgid:6401 ppid:5603 task_flags:0x40044c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_release+0x0/0x3c0 kernel/locking/lockdep.c:5876
Code: bf 00 00 50 00 e9 4f fe ff ff 41 bf 2f 00 00 00 e9 06 ff ff ff 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 f5 49
RSP: 0018:ffffc9000346ed60 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc9000346ee78 RCX: 0000000080000001
RDX: ffffc9000346ee01 RSI: ffffffff8177827f RDI: ffffffff8eb59c60
RBP: 1ffffffff21dca01 R08: ffffc9000346ee58 R09: ffffc9000346eeb8
R10: dffffc0000000000 R11: fffff5200068ddd9 R12: ffffc90003468000
R13: ffffffff8177827f R14: ffffc9000346ee68 R15: ffffc9000346ee68
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
__unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
free_unref_folios+0xd84/0x14a0 mm/page_alloc.c:3011
folios_put_refs+0x9e9/0xb30 mm/swap.c:1057
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1159
shmem_truncate_range mm/shmem.c:1287 [inline]
shmem_evict_inode+0x280/0xa80 mm/shmem.c:1417
evict+0x624/0xb50 fs/inode.c:825
dentry_kill+0x1b9/0x880 fs/dcache.c:826
finish_dput+0x1a/0x260 fs/dcache.c:1001
__fput+0x675/0xa50 fs/file_table.c:520
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:1009
do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
get_signal+0x121b/0x12c0 kernel/signal.c:3046
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faeb499e0d9
RSP: 002b:00007faeb57bd0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007faeb4c26098 RCX: 00007faeb499e0d9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007faeb4c26098
RBP: 00007faeb4c26090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faeb4c26128 R14: 00007ffe6fc9c380 R15: 00007ffe6fc9c468
task:udevd state:R running task stack:25216 pid:4971 tgid:4971 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:unwind_next_frame+0x17b/0x2550 arch/x86/kernel/unwind_orc.c:510
Code: e8 03 48 89 04 24 42 0f b6 04 20 84 c0 0f 85 92 1c 00 00 4c 89 7c 24 10 4c 89 6c 24 50 0f b6 1b 48 8b 44 24 20 42 80 3c 20 00 <4d> 8d 7e 48 74 08 4c 89 ff e8 47 18 bd 00 49 8b 2f 48 83 f3 01 48
RSP: 0018:ffffc9000469f940 EFLAGS: 00000246
RAX: 1ffff920008d3f46 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 000000005a44979c RSI: ffffffff8c4bbd60 RDI: ffffffff8c4bbd20
RBP: 1ffff920008d3f44 R08: ffffffff8177827f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000
R13: ffffffff8177827f R14: ffffc9000469f9e8 R15: 1ffff920008d3f3d
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
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2677 [inline]
slab_free mm/slub.c:6377 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6504
class_filename_destructor include/linux/fs.h:2564 [inline]
class_filename_flags_destructor include/linux/fs.h:2566 [inline]
do_readlinkat+0x451/0x510 fs/stat.c:594
__do_sys_readlink fs/stat.c:605 [inline]
__se_sys_readlink fs/stat.c:602 [inline]
__x64_sys_readlink+0x7f/0x90 fs/stat.c:602
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f605e7153a7
RSP: 002b:00007ffca76faa18 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffca76faef0 RCX: 00007f605e7153a7
RDX: 0000000000000400 RSI: 00007ffca76faa20 RDI: 00007ffca76faef0
RBP: 00007ffca76faa20 R08: 0000000000000073 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400
R13: 0000000000000100 R14: 000055d4201c3be0 R15: 00007ffca76fb970
rcu: rcu_preempt kthread starved for 10502 jiffies! g21621 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 6422 Comm: syz.2.143 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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 53 bc 3d 0a e8 de aa 39 00 fb 4c 8b 65 c8 <49> 8d bc 24 f8 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc9000341f7a0 EFLAGS: 00000206
RAX: 0000000004e0e863 RBX: ffff8880b863bf20 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8e2283d3 RDI: ffffffff8c4bbd80
RBP: ffffc9000341f7f0 R08: ffffffff90574437 R09: 1ffffffff20ae886
R10: dffffc0000000000 R11: fffffbfff20ae887 R12: ffff888025900000
R13: ffff888025900000 R14: dffffc0000000000 R15: 1ffff110170c77e4
FS: 00007f5340ac66c0(0000) GS:ffff888124f55000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 0000000052638000 CR4: 0000000000350ef0
Call Trace:
context_switch kernel/sched/core.c:5513 [inline]
__schedule+0x17e1/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
futex_do_wait kernel/futex/waitwake.c:387 [inline]
__futex_wait+0x1d3/0x400 kernel/futex/waitwake.c:722
futex_wait+0x121/0x390 kernel/futex/waitwake.c:750
do_futex+0x3e7/0x4e0 kernel/futex/syscalls.c:133
__do_sys_futex kernel/futex/syscalls.c:210 [inline]
__se_sys_futex+0x3a8/0x450 kernel/futex/syscalls.c:191
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f533fb9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5340ac60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f533fe25fa8 RCX: 00007f533fb9e0d9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f533fe25fa8
RBP: 00007f533fe25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f533fe26038 R14: 00007ffc3b4a3020 R15: 00007ffc3b4a3108