rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3936/1:b..l P18784
rcu: (detected by 0, t=10502 jiffies, g=88665, q=886 ncpus=2)
task:syz.0.3449 state:R running task stack:25848 pid:18784 tgid:18783 ppid:16316 task_flags:0x400140 flags:0x00080000
Call Trace:
sched_show_task kernel/sched/core.c:7819 [inline]
sched_show_task+0x423/0x630 kernel/sched/core.c:7794
rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline]
print_other_cpu_stall kernel/rcu/tree_stall.h:681 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:856 [inline]
rcu_pending kernel/rcu/tree.c:3667 [inline]
rcu_sched_clock_irq+0x2634/0x31f0 kernel/rcu/tree.c:2704
update_process_times+0x178/0x2d0 kernel/time/timer.c:2474
tick_sched_handle kernel/time/tick-sched.c:298 [inline]
tick_nohz_handler+0x506/0x720 kernel/time/tick-sched.c:319
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x64e/0xc40 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872
Code: b4 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 22 b9 ee 0e 0f 82 74 02 00 00 8b 35 ba e9 ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 b4 18 12 0f 85 ad 02 00 00 48 83 c4
RSP: 0018:ffffc9000c72f5b0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 00000000bf3fbf97
RDX: 0000000000000000 RSI: ffffffff8daa7ea1 RDI: ffffffff8bf2b400
RBP: 0000000000000002 R08: 00000000ac0d5af0 R09: 000000000ac0d5af
R10: 0000000000000002 R11: ffff888032bbaff0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
____bpf_get_current_cgroup_id kernel/bpf/helpers.c:411 [inline]
bpf_get_current_cgroup_id+0x35/0x3b0 kernel/bpf/helpers.c:406
bpf_prog_0fdc9c46880d420c+0x4e/0x56
__bpf_prog_run include/linux/filter.h:723 [inline]
bpf_prog_run_xdp include/net/xdp.h:696 [inline]
xdp_test_run_batch.constprop.0+0x7bb/0x1f20 net/bpf/test_run.c:307
bpf_test_run_xdp_live+0x365/0x770 net/bpf/test_run.c:379
bpf_prog_test_run_xdp+0xd3d/0x1660 net/bpf/test_run.c:1388
bpf_prog_test_run kernel/bpf/syscall.c:4703 [inline]
__sys_bpf+0x1035/0x4980 kernel/bpf/syscall.c:6182
__do_sys_bpf kernel/bpf/syscall.c:6274 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6272 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:6272
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb084d8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb085cbd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fb084fe5fa0 RCX: 00007fb084d8f749
RDX: 0000000000000050 RSI: 0000200000000b80 RDI: 000000000000000a
RBP: 00007fb084e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb084fe6038 R14: 00007fb084fe5fa0 R15: 00007ffd2f571108
task:kworker/u8:15 state:R running task stack:23176 pid:3936 tgid:3936 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:228 [inline]
RIP: 0010:unwind_next_frame+0x1f6/0x20b0 arch/x86/kernel/unwind_orc.c:510
Code: 89 c3 39 d0 0f 83 17 16 00 00 48 ba 00 00 00 00 00 fc ff df 89 c1 48 8d 3c 8d 58 9c dc 91 49 89 f8 49 c1 e8 03 45 0f b6 04 10 <48> 89 fa 83 e2 07 83 c2 03 44 38 c2 7c 2f 45 84 c0 74 2a 48 89 4c
RSP: 0018:ffffc9000df37258 EFLAGS: 00000a06
RAX: 000000000000637a RBX: 0000000000000001 RCX: 000000000000637a
RDX: dffffc0000000000 RSI: 00000000000a7c25 RDI: ffffffff91de2a40
RBP: ffffc9000df37360 R08: 0000000000000000 R09: 000000004bba0bef
R10: 0000000000000002 R11: 000000000000637a R12: ffffc9000df37368
R13: ffffc9000df37318 R14: ffffc9000df3734d R15: ffffffff81637ab2
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:339 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270
kmem_alloc_batch+0x49/0x170 lib/debugobjects.c:371
fill_pool lib/debugobjects.c:403 [inline]
debug_objects_fill_pool lib/debugobjects.c:725 [inline]
debug_objects_fill_pool+0x413/0x660 lib/debugobjects.c:697
debug_object_activate+0x10b/0x4c0 lib/debugobjects.c:814
debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
__call_rcu_common.constprop.0+0x35/0xa10 kernel/rcu/tree.c:3104
slab_free_hook mm/slub.c:2504 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x171/0x770 mm/slub.c:6781
__io_req_caches_free+0x19e/0x5c0 io_uring/io_uring.c:2826
io_req_caches_free io_uring/io_uring.c:2838 [inline]
io_ring_exit_work+0x33c/0x1130 io_uring/io_uring.c:3024
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: rcu_preempt kthread starved for 10587 jiffies! g88665 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:28120 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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 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:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline]
RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline]
RIP: 0010:native_apic_msr_write arch/x86/include/asm/apic.h:212 [inline]
RIP: 0010:native_apic_msr_write+0x28/0x40 arch/x86/include/asm/apic.h:206
Code: 90 90 f3 0f 1e fa 8d 87 30 ff ff ff 83 e0 ef 74 20 89 f8 83 e0 ef 83 f8 20 74 16 c1 ef 04 31 d2 89 f0 8d 8f 00 08 00 00 0f 30 <66> 90 e9 91 16 10 0a e9 8c 16 10 0a 89 f6 31 d2 89 cf e9 61 f1 76
RSP: 0018:ffffc90000a08ec8 EFLAGS: 00000046
RAX: 0000000000005bbf RBX: ffff8880b8523f40 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 0000000000005bbf RDI: 0000000000000038
RBP: 0000000000005bbf R08: 0000000000000005 R09: 000000000000003f
R10: 0000000000000020 R11: ffff88801dac2ff0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000020 R15: ffff8880b8528440
FS: 0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b307f7ff8 CR3: 0000000033535000 CR4: 00000000003526f0
Call Trace:
apic_write arch/x86/include/asm/apic.h:409 [inline]
lapic_next_event+0x10/0x20 arch/x86/kernel/apic/apic.c:418
clockevents_program_event+0x26e/0x370 kernel/time/clockevents.c:334
tick_program_event+0xa9/0x140 kernel/time/tick-oneshot.c:48
hrtimer_interrupt+0x3e9/0x8e0 kernel/time/hrtimer.c:1916
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: b6 5f 02 c3 cc cc cc cc 0f 1f 00 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 13 39 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 0000000003fb8047 RBX: 0000000000000001 RCX: ffffffff8b7826d9
RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: ffffffff8bf2b400
RBP: ffffed1003b58498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801dac2ff0 R12: 0000000000000001
R13: ffff88801dac24c0 R14: ffffffff9088b4d0 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148