rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21957/1:b..l P3003/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=97149, q=1369 ncpus=2)
task:kworker/u8:12 state:R running task stack:23432 pid:3003 tgid:3003 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: iou_exit io_ring_exit_work
Call Trace:
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6855
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7182
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:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x4e/0x330 kernel/locking/lockdep.c:5831
Code: 48 8b 05 ed f7 0e 12 48 89 44 24 30 31 c0 66 90 65 8b 05 09 f8 0e 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 92 7b ec 0e <0f> 82 74 02 00 00 8b 35 0a ac ec 0e 85 f6 0f 85 8d 00 00 00 48 8b
RSP: 0018:ffffc9000bf97490 EFLAGS: 00000297
RAX: 0000000000000000 RBX: ffffffff8e3c95a0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e3c95a0
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: ffff888030c42ff0 R11: 0000000000006c47 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]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758
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
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
kmalloc_noprof include/linux/slab.h:957 [inline]
slab_free_hook mm/slub.c:2495 [inline]
slab_free mm/slub.c:6642 [inline]
kmem_cache_free+0x148/0x7d0 mm/slub.c:6752
__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+0x387/0x10e0 io_uring/io_uring.c:3036
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
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
task:dhcpcd-run-hook state:R running task stack:27544 pid:21957 tgid:21957 ppid:21927 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6855
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7182
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:stack_access_ok+0x161/0x200 arch/x86/kernel/unwind_orc.c:398
Code: 03 80 3c 02 00 0f 85 95 00 00 00 48 8b 43 10 49 39 ee 77 29 48 39 e8 76 24 4c 01 e5 48 39 e8 0f 93 c0 49 39 ee 0f 92 c2 21 d0 <48> 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 83 c4
RSP: 0018:ffffc90010d7f308 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc90010d7f3b8 RCX: ffffc90010d80000
RDX: ffffc90010d7fb01 RSI: ffffc90010d7fb60 RDI: ffffc90010d7f3b8
RBP: ffffc90010d7fb60 R08: 0000000000000001 R09: 0000000079bf4ce3
R10: ffff88802df954b0 R11: 0000000000007a8c R12: 0000000000000008
R13: ffffc90010d7f3c8 R14: ffffc90010d7f3c0 R15: ffffc90010d78000
deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
unwind_next_frame+0x15c5/0x20a0 arch/x86/kernel/unwind_orc.c:648
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:559
slab_free_hook mm/slub.c:2504 [inline]
slab_free mm/slub.c:6642 [inline]
kmem_cache_free+0x15f/0x7d0 mm/slub.c:6752
anon_vma_free mm/rmap.c:136 [inline]
__put_anon_vma+0x114/0x3a0 mm/rmap.c:2777
put_anon_vma include/linux/rmap.h:117 [inline]
unlink_anon_vmas+0x58a/0x820 mm/rmap.c:443
free_pgtables+0x212/0xc00 mm/memory.c:414
exit_mmap+0x3f4/0xb60 mm/mmap.c:1291
__mmput+0x12a/0x410 kernel/fork.c:1131
mmput+0x62/0x70 kernel/fork.c:1154
exec_mmap fs/exec.c:901 [inline]
begin_new_exec+0x1280/0x3730 fs/exec.c:1156
load_elf_binary+0x8e7/0x4fe0 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve fs/exec.c:1753 [inline]
bprm_execve+0x8c2/0x1620 fs/exec.c:1729
do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x8e/0xb0 fs/exec.c:2004
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: 0033:0x7f7fe2cd9107
RSP: 002b:00007ffdc60449f8 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055bc77608e88 RCX: 00007f7fe2cd9107
RDX: 000055bc77608ea8 RSI: 000055bc77608e88 RDI: 000055bc77608f30
RBP: 000055bc77608f30 R08: 00007ffdc6047eac R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 000055bc77608ea8
R13: 00007f7fe2e9ee8b R14: 000055bc77608ea8 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10575 jiffies! g97149 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:27928 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6855
__schedule_loop kernel/sched/core.c:6937 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6952
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:
CPU: 1 UID: 0 PID: 21947 Comm: syz.2.4162 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:vcpu_enter_guest arch/x86/kvm/x86.c:11411 [inline]
RIP: 0010:vcpu_run+0x3052/0x56d0 arch/x86/kvm/x86.c:11611
Code: b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 a0 25 00 00 41 c6 86 32 0c 00 00 01 e8 66 46 84 00 fb 48 8b 95 c0 fe ff ff <48> b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 62 25
RSP: 0018:ffffc90010d6faa0 EFLAGS: 00000202
RAX: 00000000023b0461 RBX: ffff888044638c32 RCX: 0000000000000006
RDX: ffff888044639d08 RSI: ffffffff8daa2b8e RDI: ffffffff8bf1cd00
RBP: ffffc90010d6fc10 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9085c3d7 R11: 0000000000000000 R12: dffffc0000000000
R13: 0001000000000000 R14: ffff888044638000 R15: ffff888044638038
FS: 00007f8b4a8db6c0(0000) GS:ffff888124a9c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005ee17000 CR4: 00000000003526f0
DR0: 0000000000000001 DR1: 00000000000001f8 DR2: 0000000000000000
DR3: 0000000000000f5e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
kvm_arch_vcpu_ioctl_run+0xfd3/0x1860 arch/x86/kvm/x86.c:11956
kvm_vcpu_ioctl+0x5eb/0x1660 virt/kvm/kvm_main.c:4477
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
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: 0033:0x7f8b4998f749
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:00007f8b4a8db038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8b49be5fa0 RCX: 00007f8b4998f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f8b49a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b49be6038 R14: 00007f8b49be5fa0 R15: 00007ffde334c728