rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11219/1:b..l rcu: (detected by 1, t=10502 jiffies, g=36709, q=87 ncpus=2) task:vhost-11217 state:R running task stack:28728 pid:11219 tgid:11216 ppid:5825 task_flags:0x404040 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x118d/0x5df0 kernel/sched/core.c:6954 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7281 irqentry_exit+0x36/0x90 kernel/entry/common.c:196 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:stack_access_ok+0x16d/0x200 arch/x86/kernel/unwind_orc.c:398 Code: 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 08 31 c0 5b 5d 41 5c 41 5d 41 5e 41 RSP: 0018:ffffc9000525f7b8 EFLAGS: 00000296 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffc90005260000 RDX: ffffc9000525fc01 RSI: ffffc9000525fc50 RDI: ffffc9000525f838 RBP: ffffc9000525fc50 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000085e31 R12: ffffc9000525f888 R13: ffffc9000525f838 R14: ffffc9000525fc78 R15: ffffc90005258000 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:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4745 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1110 __kfree_skb net/core/skbuff.c:1167 [inline] sk_skb_reason_drop+0x136/0x1a0 net/core/skbuff.c:1204 kfree_skb_reason include/linux/skbuff.h:1275 [inline] kfree_skb include/linux/skbuff.h:1284 [inline] vhost_vsock_handle_tx_kick+0x819/0xc00 drivers/vhost/vsock.c:541 vhost_run_work_list+0x18b/0x230 drivers/vhost/vhost.c:407 vhost_task_fn+0x165/0x460 kernel/vhost_task.c:49 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 9765 jiffies! g36709 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x118d/0x5df0 kernel/sched/core.c:6954 __schedule_loop kernel/sched/core.c:7036 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7051 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 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: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller-04405-g4b290aae788e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 3b 67 02 e9 43 0b 03 00 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 c3 6c 1f 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6 RAX: 0000000003eb91f7 RBX: 0000000000000001 RCX: ffffffff8b8aac99 RDX: 0000000000000000 RSI: ffffffff8de0e9cd RDI: ffffffff8c15ed80 RBP: ffffed1003c55488 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e2aa440 R14: ffffffff90a7bf50 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124822000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff3c6453154 CR3: 000000005bad6000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148