rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=31dc/1/0x4000000000000000 softirq=44387/44388 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9084/1:b..l
rcu: (detected by 0, t=10505 jiffies, g=28013, q=213 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5233 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217
Code: 5b e9 33 e2 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 10 c2 92 <65> 8b 15 48 81 01 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc90000a08d38 EFLAGS: 00000002
RAX: ffffffff81ae9b1e RBX: ffff8880b8727bc8 RCX: ffff8880660cda00
RDX: ffff8880660cda00 RSI: ffffffff8c035860 RDI: ffffffff8c035820
RBP: ffffc90000a08e90 R08: ffffffff8fc40337 R09: 1ffffffff1f88066
R10: dffffc0000000000 R11: fffffbfff1f88067 R12: ffff888034642340
R13: 0000000000000000 R14: ffffffff899f7160 R15: 0000000000000001
FS: 00007fe1eb543880(0000) GS:ffff888125aff000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdddbf72020 CR3: 0000000033f24000 CR4: 00000000003526f0
Call Trace:
trace_hrtimer_expire_entry include/trace/events/timer.h:259 [inline]
__run_hrtimer kernel/time/hrtimer.c:1758 [inline]
__hrtimer_run_queues+0x47e/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:217 [inline]
RIP: 0010:unwind_next_frame+0x20c/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 4d 89 e7 49 29 c7 49 c1 ef 08 8b 15 9e af 6a 0c 8d 42 ff 44 39 f8 0f 86 65 18 00 00 44 89 f8 4c 8d 2c 85 64 fd 00 91 4c 89 e8 <48> c1 e8 03 0f b6 04 28 84 c0 48 89 eb 0f 85 1c 1c 00 00 45 8b 6d
RSP: 0018:ffffc90003327858 EFLAGS: 00000202
RAX: ffffffff9100fd68 RBX: 0000000000000001 RCX: 7178c3ef17208c00
RDX: 00000000000a826f RSI: ffffffff8c035860 RDI: ffffffff8c035820
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90003327978 R11: ffffffff81ad2180 R12: ffffffff8100012f
R13: ffffffff9100fd68 R14: ffffc90003327928 R15: 0000000000000001
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
__kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5b/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2417 [inline]
slab_free mm/slub.c:4680 [inline]
kfree+0x18e/0x440 mm/slub.c:4879
seq_release+0x54/0x70 fs/seq_file.c:355
kernfs_fop_release+0x133/0x190 fs/kernfs/file.c:766
__fput+0x449/0xa70 fs/file_table.c:468
fput_close_sync+0x119/0x200 fs/file_table.c:573
__do_sys_close fs/open.c:1587 [inline]
__se_sys_close fs/open.c:1572 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1572
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: 0033:0x7fe1eaf15a67
Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 ca 19 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 61 b3 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffe70c22e48 EFLAGS: 00000297 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000562d09b9d8a0 RCX: 00007fe1eaf15a67
RDX: 00007fe1eafefea0 RSI: 0000562d09ba1550 RDI: 000000000000000c
RBP: 00007fe1eafefff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000
R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544
task:syz.5.468 state:R running task stack:22208 pid:9084 tgid:9084 ppid:6334 task_flags:0x40064c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x387/0x2390 arch/x86/kernel/unwind_orc.c:505
Code: 37 01 00 00 4c 8d 62 04 4c 8d 6a 05 4c 89 e0 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 6d 19 00 00 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 80 19 00 00 41 0f b6 44 24 01 83 e0 07 0f 84 75 15 00
RSP: 0018:ffffc90002f26d98 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffffff8fdf13b4 RCX: ffffffff8fdf13b8
RDX: ffffffff905ec97e RSI: ffffffff905ec97e RDI: ffffffff8c035820
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90002f26eb8 R11: ffffffff81ad2180 R12: ffffffff905ec982
R13: ffffffff905ec983 R14: ffffc90002f26e68 R15: ffffffff8fdf13b4
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2952
folios_put_refs+0x559/0x640 mm/swap.c:997
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1157
shmem_truncate_range mm/shmem.c:1269 [inline]
shmem_evict_inode+0x272/0xa70 mm/shmem.c:1397
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:961
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73
exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fd681b8ebf1
RSP: 002b:fffffffffffffef0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fd681db5fa0 RCX: 00007fd681b8ebe9
RDX: 0000000000000000 RSI: fffffffffffffef0 RDI: 0000000000a00200
RBP: 00007fd681c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fd681db6038 R14: 00007fd681db5fa0 R15: 00007ffec926d318
rcu: rcu_preempt kthread starved for 10505 jiffies! g28013 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:26760 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 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+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 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:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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 83 8f 29 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:ffffffff8e007d80 EFLAGS: 000002c2
RAX: a2f7837e5555e200 RBX: ffffffff81976c78 RCX: a2f7837e5555e200
RDX: 0000000000000001 RSI: ffffffff8c035860 RDI: ffffffff81976c78
RBP: ffffffff8e007ea8 R08: ffff8880b8632f9b R09: 1ffff110170c65f3
R10: dffffc0000000000 R11: ffffed10170c65f4 R12: ffffffff8fc40330
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1c12a38
FS: 0000000000000000(0000) GS:ffff8881259ff000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f942d0bb000 CR3: 0000000067646000 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
rest_init+0x2de/0x300 init/main.c:756
start_kernel+0x3a9/0x410 init/main.c:1109
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x147