rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1137/1:b..l P7120/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=62161, q=442 ncpus=2)
task:syz-executor state:R running task stack:20480 pid:7120 tgid:7120 ppid:7114 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5263 [inline]
__schedule+0x1836/0x4ed0 kernel/sched/core.c:6871
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7198
irqentry_exit+0x5b5/0x640 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2ac/0x3d0 kernel/locking/lockdep.c:5893
Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 b4 ec d7 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000416f2d8 EFLAGS: 00000206
RAX: dd26c90bce21db00 RBX: 0000000000000202 RCX: dd26c90bce21db00
RDX: 0000000000000003 RSI: ffffffff8d9761d1 RDI: ffffffff8bbf80e0
RBP: ffff88807d58aa28 R08: 0000000000000000 R09: ffffffff81ac1ccd
R10: ffffc9000416f418 R11: ffffffff81ada5d0 R12: 0000000000000003
R13: 0000000000000003 R14: ffffffff8df3d9c0 R15: ffff88807d589e80
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
is_module_text_address+0x18b/0x1e0 kernel/module/main.c:3858
kernel_text_address+0x94/0xe0 kernel/extable.c:119
__kernel_text_address+0xd/0x40 kernel/extable.c:79
unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369
arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26
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
unpoison_slab_object mm/kasan/common.c:339 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4948 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
kmem_cache_alloc_noprof+0x37d/0x700 mm/slub.c:5265
anon_vma_chain_alloc mm/rmap.c:141 [inline]
anon_vma_fork+0x1f1/0x500 mm/rmap.c:363
dup_mmap+0x94f/0x1b00 mm/mmap.c:1788
dup_mm kernel/fork.c:1488 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1540
copy_process+0x1663/0x3930 kernel/fork.c:2180
kernel_clone+0x21e/0x850 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f56385e93
RSP: 002b:00007ffd2f5e3d28 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4f56385e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055556f0e67d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000008b684 R15: 00007ffd2f5e3ec0
task:kworker/u8:8 state:R running task stack:19904 pid:1137 tgid:1137 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
context_switch kernel/sched/core.c:5263 [inline]
__schedule+0x1836/0x4ed0 kernel/sched/core.c:6871
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7198
irqentry_exit+0x5b5/0x640 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x16c/0x350 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 14 ff d7 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003e8f298 EFLAGS: 00000206
RAX: 158b1d59a25da200 RBX: 0000000000000000 RCX: 158b1d59a25da200
RDX: 0000000000000000 RSI: ffffffff8d9761d1 RDI: ffffffff8bbf80e0
RBP: ffffffff81741ff5 R08: 0000000000000000 R09: ffffffff81741ff5
R10: ffffc90003e8f458 R11: ffffffff81ada5d0 R12: 0000000000000002
R13: ffffffff8df3d9c0 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
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
kasan_kmalloc include/linux/kasan.h:262 [inline]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5771
kmalloc_noprof include/linux/slab.h:957 [inline]
slab_free_hook mm/slub.c:2492 [inline]
slab_free mm/slub.c:6663 [inline]
kmem_cache_free+0x16b/0x640 mm/slub.c:6774
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2821
io_req_caches_free+0x21/0x60 io_uring/io_uring.c:2833
io_ring_exit_work+0x3b3/0x8d0 io_uring/io_uring.c:3019
process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261
process_scheduled_works kernel/workqueue.c:3344 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425
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: rcu_preempt kthread starved for 10255 jiffies! g62161 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:26904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5263 [inline]
__schedule+0x1836/0x4ed0 kernel/sched/core.c:6871
__schedule_loop kernel/sched/core.c:6953 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6968
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:
CPU: 1 UID: 0 PID: 10782 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcd4/0x12d0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 3a 95 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 e5 90 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 c9 90 0b 00 eb e4 44
RSP: 0000:ffffc90004d17740 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170c8529 RCX: ffff88807a135b80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004d178c0 R08: ffffffff8f7deb77 R09: 1ffffffff1efbd6e
R10: dffffc0000000000 R11: fffffbfff1efbd6f R12: ffff8880b8642948
R13: dffffc0000000000 R14: ffff8880b873b900 R15: 0000000000000000
FS: 000055556656d500(0000) GS:ffff888125fb9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555665885c8 CR3: 00000000446ba000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1472
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:103
wp_page_copy mm/memory.c:3783 [inline]
do_wp_page+0x1bac/0x5800 mm/memory.c:4178
handle_pte_fault mm/memory.c:6287 [inline]
__handle_mm_fault mm/memory.c:6409 [inline]
handle_mm_fault+0x14c8/0x32c0 mm/memory.c:6578
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: 0033:0x7f3f72f4daaf
Code: 8d 34 19 48 39 d5 48 89 75 60 0f 95 c2 48 29 d8 48 83 c1 10 0f b6 d2 48 83 c8 01 48 c1 e2 02 48 09 da 48 83 ca 01 48 89 51 f8 <48> 89 46 08 eb 80 48 8d 0d 51 00 0f 00 48 8d 15 55 12 0f 00 bf 01
RSP: 002b:00007ffe64700600 EFLAGS: 00010206
RAX: 0000000000018a41 RBX: 0000000000008040 RCX: 0000555566580590
RDX: 0000000000008041 RSI: 00005555665885c0 RDI: 0000000000000004
RBP: 00007f3f731bacc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000802 R12: 0000000000008030
R13: 0000000000000076 R14: 00007f3f731bad20 R15: 0000000000000000