rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6488/3:b..l P6402/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=15901, q=1181 ncpus=2)
task:udevd state:R running task stack:25240 pid:6402 tgid:6402 ppid:5199 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
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 44 91 25 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003007878 EFLAGS: 00000206
RAX: 6644636aa7897f00 RBX: 0000000000000000 RCX: 6644636aa7897f00
RDX: 000000005a44979c RSI: ffffffff8dc93c7b RDI: ffffffff8be247e0
RBP: ffffffff81746f85 R08: ffffffff81746f85 R09: ffffffff8e33f2e0
R10: ffffc90003007a38 R11: ffffffff81addd50 R12: 0000000000000002
R13: ffffffff8e33f2e0 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+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
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:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 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:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6785
do_readlinkat+0x293/0x500 fs/stat.c:596
__do_sys_readlink fs/stat.c:613 [inline]
__se_sys_readlink fs/stat.c:610 [inline]
__x64_sys_readlink+0x7f/0x90 fs/stat.c:610
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: 0033:0x7f4ce62473a7
RSP: 002b:00007ffc34961158 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffc34961b30 RCX: 00007f4ce62473a7
RDX: 0000000000000400 RSI: 00007ffc34961610 RDI: 00007ffc34961b30
RBP: 00007ffc34961b41 R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000246 R12: 00007ffc34961610
R13: 00007ffc34961210 R14: 000055e30c7bd6d7 R15: 000055e3107fd460
task:dhcpcd-run-hook state:R running task stack:27832 pid:6488 tgid:6488 ppid:6481 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074
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]
filemap_map_pages+0x1939/0x1fa0 mm/filemap.c:3931
do_fault_around mm/memory.c:5713 [inline]
do_read_fault mm/memory.c:5746 [inline]
do_fault mm/memory.c:5889 [inline]
do_pte_missing+0x20b2/0x3330 mm/memory.c:4401
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: 0033:0x7fbf17430000
RSP: 002b:00007ffdf356a1b0 EFLAGS: 00010246
RAX: 000056140047c250 RBX: 0000000000000004 RCX: 0000000000000003
RDX: 0000561400473910 RSI: 000000000000002f RDI: 000056140047c250
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000020
R10: 0000000000000040 R11: 0000000000000000 R12: 00005614004754f0
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10526 jiffies! g15901 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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: 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 33 0e 21 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: f34c606417fb5000 RBX: ffffffff8197c6ba RCX: f34c606417fb5000
RDX: 0000000000000001 RSI: ffffffff8daa9dc3 RDI: ffffffff8be247e0
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fc3d070
R13: 1ffff11003adcb70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f256a7b1f98 CR3: 000000007b982000 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
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147