rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7871/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=30329, q=741 ncpus=2)
task:syz.6.292 state:R running task stack:25208 pid:7871 tgid:7870 ppid:6971 task_flags:0x400140 flags:0x00080006
Call Trace:
context_switch kernel/sched/core.c:5290 [inline]
__schedule+0x14db/0x5030 kernel/sched/core.c:6902
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7229
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2d8/0x3b0 kernel/locking/lockdep.c:5893
Code: 24 04 11 00 00 00 00 eb b5 e8 54 10 c0 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 74 de 03 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 59 ec c2 09 cc 48 8d 3d 81 91 07
RSP: 0000:ffffc9000b6bef00 EFLAGS: 00000286
RAX: a704ae4185c94100 RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000001 RSI: ffffffff8db8bddd RDI: ffffffff8be09760
RBP: ffff88802cbda970 R08: ffffc9000b6bf3a0 R09: 0000000000000000
R10: ffffc9000b6bf058 R11: fffff520016d7e0d R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8e144ce0 R15: ffff88802cbd9e40
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock include/linux/rcupdate.h:881 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695
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
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:5187 [inline]
slab_alloc_node mm/slub.c:5500 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5507
alloc_empty_file+0x55/0x1d0 fs/file_table.c:237
path_openat+0x108/0x3840 fs/namei.c:4814
do_file_open+0x203/0x440 fs/namei.c:4857
io_openat2+0x408/0x6b0 io_uring/openclose.c:141
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1770
io_issue_sqe+0x165/0xf50 io_uring/io_uring.c:1793
io_queue_sqe io_uring/io_uring.c:2020 [inline]
io_submit_sqe io_uring/io_uring.c:2300 [inline]
io_submit_sqes+0xc33/0x2350 io_uring/io_uring.c:2414
__do_sys_io_uring_enter io_uring/io_uring.c:3268 [inline]
__se_sys_io_uring_enter+0x2fd/0x2bb0 io_uring/io_uring.c:3203
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa39318f749
RSP: 002b:00007fa394006038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007fa3933e5fa0 RCX: 00007fa39318f749
RDX: 0000000000000000 RSI: 0000000000007277 RDI: 0000000000000005
RBP: 00007fa393213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000028 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3933e6038 R14: 00007fa3933e5fa0 R15: 00007ffd394117e8
rcu: rcu_preempt kthread starved for 7006 jiffies! g30329 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:28096 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5290 [inline]
__schedule+0x14db/0x5030 kernel/sched/core.c:6902
__schedule_loop kernel/sched/core.c:6984 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6999
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 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:
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:__rq_lockp kernel/sched/sched.h:1455 [inline]
RIP: 0010:raw_spin_rq_lock_nested+0xd1/0x150 kernel/sched/core.c:656
Code: 8b 6d 00 48 8d 7d 48 48 89 7c 24 08 89 de e8 56 34 d0 09 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 07 84 c0 75 5d 48 8b 04 24 <83> 38 00 4c 89 f0 74 1d 48 b8 00 00 00 00 00 fc ff df 41 80 3c 04
RSP: 0018:ffffc90000197a78 EFLAGS: 00000046
RAX: ffff8880b873b9b0 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000197a00
RBP: ffff8880b863ab80 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000032f40 R12: 1ffff110170e7733
R13: ffff8880b873b998 R14: ffff8880b873ab80 R15: 1ffff110170e7736
FS: 0000000000000000(0000) GS:ffff888125cf9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3c607d5d58 CR3: 00000000281fc000 CR4: 00000000003526f0
Call Trace:
raw_spin_rq_lock kernel/sched/sched.h:1613 [inline]
raw_spin_rq_lock_irq kernel/sched/sched.h:1620 [inline]
sched_core_balance+0xc71/0xe00 kernel/sched/core.c:6328
do_balance_callbacks kernel/sched/core.c:4925 [inline]
__balance_callbacks kernel/sched/core.c:4979 [inline]
finish_lock_switch kernel/sched/core.c:5026 [inline]
finish_task_switch+0x408/0x950 kernel/sched/core.c:5145
context_switch kernel/sched/core.c:5293 [inline]
__schedule+0x14e3/0x5030 kernel/sched/core.c:6902
schedule_idle+0x52/0x90 kernel/sched/core.c:7025
do_idle+0x472/0x4d0 kernel/sched/idle.c:360
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