rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P28738/1:b..l rcu: (detected by 0, t=10502 jiffies, g=125557, q=338 ncpus=2) task:vhost-28737 state:R running task stack:27360 pid:28738 tgid:28736 ppid:9979 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0xee5/0x59b0 kernel/sched/core.c:6688 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6865 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 unwind_next_frame+0x1c7a/0x2390 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 save_stack+0x15e/0x1f0 mm/page_owner.c:128 __reset_page_owner+0x5a/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1137 [inline] free_unref_page_prepare+0x4f8/0xa90 mm/page_alloc.c:2383 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2523 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x180/0x3d0 mm/slub.c:3523 __alloc_skb+0x287/0x330 net/core/skbuff.c:641 alloc_skb include/linux/skbuff.h:1286 [inline] virtio_vsock_alloc_skb include/linux/virtio_vsock.h:67 [inline] vhost_vsock_alloc_skb drivers/vhost/vsock.c:348 [inline] vhost_vsock_handle_tx_kick+0x3ef/0xbe0 drivers/vhost/vsock.c:519 vhost_worker+0x17c/0x200 drivers/vhost/vhost.c:411 vhost_task_fn+0x169/0x370 kernel/vhost_task.c:55 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: rcu_preempt kthread starved for 337 jiffies! g125557 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:27696 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0xee5/0x59b0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0xe5/0x270 kernel/sched/core.c:6778 schedule_timeout+0x156/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:1626 rcu_gp_kthread+0x243/0x380 kernel/rcu/tree.c:1825 kthread+0x337/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 13056 Comm: syz-executor.5 Not tainted 6.6.0-rc7-next-20231026-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3f1/0xc70 kernel/locking/qspinlock.c:511 Code: c6 43 01 01 41 be 00 80 00 00 48 c1 e9 03 41 83 e4 07 41 bd 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 3c 01 eb 0c f3 90 <41> 83 ee 01 0f 84 c2 04 00 00 41 0f b6 07 44 38 e0 7f 08 84 c0 0f RSP: 0018:ffffc90000007710 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff888016a884c0 RCX: 1ffff11002d51098 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff888016a884c2 RBP: ffff8880b983d580 R08: ffff888016a884c1 R09: ffff8880b983d580 R10: ffff888016a884c3 R11: 0000000000100010 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000006143 R15: ffffed1002d51098 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffef3a9fce8 CR3: 000000002967b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x20c/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:351 [inline] __netif_tx_lock include/linux/netdevice.h:4377 [inline] __dev_queue_xmit+0x1a8e/0x3d20 net/core/dev.c:4340 dev_queue_xmit include/linux/netdevice.h:3108 [inline] can_send+0x77c/0xb40 net/can/af_can.c:276 can_can_gw_rcv+0x74c/0xab0 net/can/gw.c:561 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x15e/0x8e0 net/can/af_can.c:599 can_receive+0x320/0x5c0 net/can/af_can.c:663 can_rcv+0x1dc/0x270 net/can/af_can.c:687 __netif_receive_skb_one_core+0x115/0x180 net/core/dev.c:5527 __netif_receive_skb+0x1f/0x1b0 net/core/dev.c:5641 process_backlog+0x101/0x6b0 net/core/dev.c:5969 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6531 napi_poll net/core/dev.c:6600 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6733 __do_softirq+0x216/0x95f kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb5/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 76 f2 e3 f6 48 89 df e8 ae 71 e4 f6 f7 c5 00 02 00 00 75 1f 9c 58 f6 c4 02 75 2f 01 00 00 00 e8 25 bc d5 f6 65 8b 05 06 69 7e 75 85 c0 74 12 5b RSP: 0018:ffffc9000ab16fc8 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffffffff92a2e508 RCX: 1ffffffff23e4a5c RDX: 0000000000000000 RSI: ffffffff8accbda0 RDI: ffffffff8b2e8d00 RBP: 0000000000000286 R08: 0000000000000001 R09: fffffbfff23e23d5 R10: ffffffff91f11eaf R11: 1ffff11006982140 R12: dffffc0000000000 R13: dead000000000122 R14: 0000000000000003 R15: 0000000000000003 __debug_check_no_obj_freed lib/debugobjects.c:1042 [inline] debug_check_no_obj_freed+0x245/0x4c0 lib/debugobjects.c:1063 free_pages_prepare mm/page_alloc.c:1143 [inline] free_unref_page_prepare+0x24f/0xa90 mm/page_alloc.c:2383 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2523 __unfreeze_partials+0x21d/0x240 mm/slub.c:2655 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x163/0x390 mm/slub.c:3502 insert_revoke_hash+0x29/0x2b0 fs/jbd2/revoke.c:145 jbd2_journal_revoke+0x2e6/0x5b0 fs/jbd2/revoke.c:402 __ext4_forget+0x1fe/0x460 fs/ext4/ext4_jbd2.c:308 ext4_free_blocks+0xfd4/0x1ac0 fs/ext4/mballoc.c:6611 ext4_remove_blocks fs/ext4/extents.c:2545 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline] ext4_ext_remove_space+0x2480/0x43a0 fs/ext4/extents.c:2958 ext4_ext_truncate+0x240/0x2e0 fs/ext4/extents.c:4408 ext4_truncate+0xdc9/0x1390 fs/ext4/inode.c:4169 ext4_evict_inode+0x7b1/0x1a50 fs/ext4/inode.c:258 evict+0x2ed/0x6b0 fs/inode.c:664 iput_final fs/inode.c:1775 [inline] iput.part.0+0x56e/0x7b0 fs/inode.c:1801 iput+0x5c/0x80 fs/inode.c:1791 dentry_unlink_inode+0x292/0x430 fs/dcache.c:401 __dentry_kill+0x3b8/0x640 fs/dcache.c:607 dentry_kill fs/dcache.c:745 [inline] dput+0x6de/0xf80 fs/dcache.c:913 __fput+0x3b9/0xbb0 fs/file_table.c:402 task_work_run+0x14c/0x240 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa85/0x2ac0 kernel/exit.c:871 do_group_exit+0xd3/0x2a0 kernel/exit.c:1021 get_signal+0x2391/0x2760 kernel/signal.c:2904 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11c/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x62/0x6a RIP: 0033:0x7fe6bf2a7ef5 Code: Unable to access opcode bytes at 0x7fe6bf2a7ecb. RSP: 002b:00007fe6c000a010 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fe6bf39c120 RCX: 00007fe6bf2a7ef5 RDX: 00007fe6c000a050 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fe6bf2c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000006e R14: 00007fe6bf39c120 R15: 00007fff6b415c08