rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6142/1:b..l P5197/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=17545, q=1088 ncpus=2)
task:udevd state:R running task stack:24888 pid:5197 tgid:5197 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7191
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_count_add+0x4/0x190 kernel/sched/core.c:5715
Code: 8b 3c 24 e8 de f1 96 00 eb 8c e9 f1 fe ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <41> 57 41 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 20 54 88 99
RSP: 0018:ffffc90002f977d8 EFLAGS: 00000293
RAX: ffffffff848a40f0 RBX: ffff8880328b8f68 RCX: ffff88807c111e80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000002 R08: ffff88803110c1e0 R09: ffff8880328b8eb0
R10: ffff88803110c1e0 R11: ffffffff82642e40 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffc90002f97a80 R15: 1ffff920005f2f51
__raw_spin_lock include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock+0x12/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
lockref_get_not_dead+0x28/0xc0 lib/lockref.c:155
__legitimize_path fs/namei.c:817 [inline]
legitimize_path fs/namei.c:827 [inline]
try_to_unlazy+0x166/0x5e0 fs/namei.c:888
may_lookup fs/namei.c:1909 [inline]
link_path_walk+0xadc/0x18d0 fs/namei.c:2537
path_lookupat+0xe4/0x8c0 fs/namei.c:2745
filename_lookup+0x212/0x570 fs/namei.c:2775
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/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2afab11b0a
RSP: 002b:00007ffdc9432028 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffdc94324c0 RCX: 00007f2afab11b0a
RDX: 00007ffdc9432030 RSI: 00007ffdc94324c0 RDI: 00000000ffffff9c
RBP: 00005616a0d9c910 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdc94320c0
R13: 0000000000000100 R14: 000056167172bbe0 R15: 00007ffdc9432b40
task:udevd state:R running task stack:23888 pid:6142 tgid:6142 ppid:5197 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7191
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2a6/0x3b0 kernel/locking/lockdep.c:5893
Code: 4d 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 52 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 5a 65 de 10 <48> 3b 44 24 28 75 75 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d e9
RSP: 0018:ffffc900053ff7d0 EFLAGS: 00000206
RAX: ab62543810b86e00 RBX: 0000000000000202 RCX: ab62543810b86e00
RDX: 0000000000000000 RSI: ffffffff8d969d83 RDI: ffffffff8bc018e0
RBP: ffff888020f94830 R08: ffffc900053ffd30 R09: 0000000000000000
R10: ffffc900053ff958 R11: fffff52000a7ff2d R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8df419e0 R15: ffff888020f93d00
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
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:584
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6663 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6774
user_path_at+0x44/0x60 fs/namei.c:3569
do_utimes_path fs/utimes.c:96 [inline]
do_utimes+0x131/0x2a0 fs/utimes.c:141
__do_sys_utimensat fs/utimes.c:160 [inline]
__se_sys_utimensat fs/utimes.c:144 [inline]
__x64_sys_utimensat+0x14f/0x230 fs/utimes.c:144
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2afab15a1a
RSP: 002b:00007ffdc94318e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000118
RAX: ffffffffffffffda RBX: 00007ffdc94322c0 RCX: 00007f2afab15a1a
RDX: 0000000000000000 RSI: 00007ffdc94322c0 RDI: 00000000ffffff9c
RBP: 00007ffdc94322cf R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000246 R12: 00007ffdc9431da0
R13: 00007ffdc94319a0 R14: 00005616717276d7 R15: 00005616a0d9d280
rcu: rcu_preempt kthread starved for 10559 jiffies! g17545 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6864
__schedule_loop kernel/sched/core.c:6946 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6961
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+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
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 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 93 ef 02 00 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 73 f0 0e 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: 0000:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: b548f74670f7af00 RBX: ffffffff8197913a RCX: b548f74670f7af00
RDX: 0000000000000001 RSI: ffffffff8d783537 RDI: ffffffff8bc018e0
RBP: ffffffff8dc07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db
R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f813370
R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e4f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b98456d58 CR3: 0000000032e42000 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:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3a7/0x400 init/main.c:1206
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