rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13856/1:b..l P13849/1:b..l P5191/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=66813, q=375 ncpus=2)
task:udevd state:R running task stack:22712 pid:5191 tgid:5191 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
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_acquire+0x16c/0x340 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 f4 e9 df 10 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900035274d8 EFLAGS: 00000206
RAX: 1b53358a8f7cc700 RBX: 0000000000000000 RCX: 1b53358a8f7cc700
RDX: 0000000096cd8dd3 RSI: ffffffff8d976b80 RDI: ffffffff8bc07960
RBP: ffffffff81743f85 R08: ffffffff81743f85 R09: ffffffff8df419e0
R10: dffffc0000000000 R11: ffffffff81ad9fb0 R12: 0000000000000002
R13: ffffffff8df419e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
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]
kfree+0x1c0/0x660 mm/slub.c:6871
tomoyo_realpath_from_path+0x598/0x5d0 security/tomoyo/realpath.c:286
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822
security_inode_getattr+0x12f/0x330 security/security.c:1869
vfs_getattr fs/stat.c:259 [inline]
vfs_fstat fs/stat.c:281 [inline]
__do_sys_newfstat fs/stat.c:555 [inline]
__se_sys_newfstat fs/stat.c:550 [inline]
__x64_sys_newfstat+0xfc/0x200 fs/stat.c:550
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: 0033:0x7f0382f11ad7
RSP: 002b:00007ffc7709fbd8 EFLAGS: 00000297 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 000055f0d6c440d0 RCX: 00007f0382f11ad7
RDX: 00007f0382fefea0 RSI: 00007ffc7709fbe0 RDI: 000000000000000c
RBP: 00007f0382fefff0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 000000000000000a
R13: 0000000000003fff R14: 0000000000000000 R15: 000055f0d6c440d0
task:syz.7.1824 state:R running task stack:25336 pid:13849 tgid:13848 ppid:10325 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
do_anonymous_page mm/memory.c:5279 [inline]
do_pte_missing+0x2a0b/0x3330 mm/memory.c:4399
handle_pte_fault mm/memory.c:6273 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f9dd42509e6
RSP: 002b:00007f9dd51704a0 EFLAGS: 00010206
RAX: 0000000000720001 RBX: 00007f9dd5170540 RCX: 00000000000000c8
RDX: 0000000000000005 RSI: 0000000000000001 RDI: 00007f9dd51705e0
RBP: 0000000000000102 R08: 00007f9dca000000 R09: 0000000000720000
R10: 0000000000000000 R11: 00007f9dd5170550 R12: 0000000000000001
R13: 00007f9dd442fc40 R14: 0000000000000000 R15: 00007f9dd51705e0
task:dhcpcd-run-hook state:R running task stack:27832 pid:13856 tgid:13856 ppid:13847 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
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:security_inode_permission+0x51/0x310 security/security.c:1814
Code: ff df 0f b6 04 08 84 c0 0f 85 97 00 00 00 45 8b 3f 44 89 fe 81 e6 00 02 00 00 31 ed 31 ff e8 86 45 82 fd 41 81 e7 00 02 00 00 <75> 72 e9 92 00 00 00 e8 33 41 82 fd 0f 1f 44 00 00 e8 29 41 82 fd
RSP: 0018:ffffc9000505f858 EFLAGS: 00000246
RAX: ffffffff843f6f6a RBX: 0000000000000081 RCX: 0000000000000000
RDX: ffff88802ededb80 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88802ededb80 R09: 0000000000000002
R10: 0000000000006000 R11: 0000000000000000 R12: 0000000000000081
R13: ffffc9000505fa80 R14: ffff888031d195d8 R15: 0000000000000000
lookup_inode_permission_may_exec fs/namei.c:639 [inline]
may_lookup fs/namei.c:1900 [inline]
link_path_walk+0xc2d/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: 0033:0x7fb7fdc6ab0a
RSP: 002b:00007ffdb7c98b98 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fb7fdc6ab0a
RDX: 00007ffdb7c98ba8 RSI: 000055bc9db85330 RDI: 00000000ffffff9c
RBP: 000055bc9db7e040 R08: 0000000000000001 R09: 3c00000040001201
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb7fddf2322
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10600 jiffies! g66813 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:26928 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
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: be 43 b5 f5 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 f3 50 0d 00 f3 0f 1e fa fb f4 93 43 b5 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: 1cb140b7723fef00 RBX: ffffffff81978eba RCX: 1cb140b7723fef00
RDX: 0000000000000001 RSI: ffffffff8d78fdf1 RDI: ffffffff8bc07960
RBP: ffffffff8dc07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db
R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f81f870
R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e3a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4796772100 CR3: 0000000057c3a000 CR4: 0000000000350ef0
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