rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (3 GPs behind) idle=6fcc/0/0x1 softirq=372719/372720 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15027/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=424705, q=501 ncpus=2)
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 05/09/2026
RIP: 0010:__netif_schedule+0x1db/0x200 net/core/dev.c:3406
Code: 4d 85 f6 75 16 e8 15 f8 48 f8 eb 15 e8 0e f8 48 f8 e8 d9 9b 2d 02 4d 85 f6 74 ea e8 ff f7 48 f8 fb 48 83 c4 08 5b 41 5c 41 5d <41> 5e 41 5f 5d e9 4b 9b 30 02 cc e8 e5 f7 48 f8 48 c7 c7 80 a0 dc
RSP: 0018:ffffc90000007cf0 EFLAGS: 00000086
RAX: ffffffff897d27f7 RBX: ffffffff89b90e68 RCX: ffffffff8e68ef40
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffff88805676319f R09: 1ffff1100acec633
R10: dffffc0000000000 R11: ffffed100acec634 R12: ffff88807d709000
R13: ffff888056763000 R14: ffff888056763208 R15: ffff888056763340
FS: 0000000000000000(0000) GS:ffff88812526a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000b4030 CR3: 000000008c396000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
advance_sched+0xa8a/0xc80 net/sched/sch_taprio.c:993
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 7c 7d 02 c3 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 03 a8 1e 00 fb f4 7c 03 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e607de0 EFLAGS: 00000246
RAX: ffff88812526a000 RBX: ffffffff819a6240 RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8c292100 RDI: ffffffff819a6240
RBP: ffffffff8e607eb8 R08: ffff8880b86338db R09: 1ffff110170c671b
R10: dffffc0000000000 R11: ffffed10170c671c R12: 0000000000000000
R13: 1ffffffff1cd1de8 R14: 1ffffffff1cc0fc4 R15: dffffc0000000000
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x2e0/0x540 kernel/sched/idle.c:355
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
rest_init+0x2de/0x300 init/main.c:717
start_kernel+0x38a/0x3e0 init/main.c:1175
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x157
task:syz.5.11957 state:R running task stack:26904 pid:15027 tgid:15024 ppid:13219 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7502
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753
trace_lock_acquire include/trace/events/lock.h:23 [inline]
lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:840 [inline]
class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
__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
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5334 [inline]
__kmalloc_noprof+0x358/0x750 mm/slub.c:5347
_kmalloc_noprof include/linux/slab.h:973 [inline]
_kzalloc_noprof include/linux/slab.h:1286 [inline]
iter_file_splice_write+0x1ea/0x1240 fs/splice.c:678
do_splice_from fs/splice.c:936 [inline]
direct_splice_actor+0x101/0x160 fs/splice.c:1159
splice_direct_to_actor+0x57b/0xcb0 fs/splice.c:1103
do_splice_direct_actor fs/splice.c:1202 [inline]
do_splice_direct+0x195/0x290 fs/splice.c:1228
do_sendfile+0x52e/0x7c0 fs/read_write.c:1371
__do_sys_sendfile64 fs/read_write.c:1426 [inline]
__se_sys_sendfile64+0xdf/0x1a0 fs/read_write.c:1418
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: 0033:0x7f74d819ce59
RSP: 002b:00007f74d63b4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f74d8416180 RCX: 00007f74d819ce59
RDX: 0000200000000080 RSI: 000000000000000a RDI: 000000000000000a
RBP: 00007f74d8232d6f R08: 0000000000000000 R09: 0000000000000000
R10: 000000004d9b6eaf R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74d8416218 R14: 00007f74d8416180 R15: 00007f74d853fa48
rcu: rcu_preempt kthread starved for 10503 jiffies! g424705 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:28056 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
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: 1 UID: 0 PID: 7168 Comm: kworker/u8:7 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
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+0x10/0x70 kernel/kcov.c:217
Code: de 5b e9 13 c2 61 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 0d b8 3e 75 11 <65> 8b 15 d9 3e 75 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc900051f7718 EFLAGS: 00000202
RAX: ffffffff81ba0887 RBX: dffffc0000000000 RCX: ffff888078f8be00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900051f7860 R08: ffffffff903142f7 R09: 1ffffffff206285e
R10: dffffc0000000000 R11: fffffbfff206285f R12: 1ffff110170c85c5
R13: ffff8880b873c2c8 R14: ffff8880b8642e28 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812536a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001c1030 CR3: 000000000e746000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000efff0f7c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
csd_lock_wait kernel/smp.c:342 [inline]
smp_call_function_many_cond+0x10c7/0x14b0 kernel/smp.c:892
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0xb27/0x1110 arch/x86/kernel/alternative.c:3045
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
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