rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6682/1:b..l rcu: (detected by 0, t=10503 jiffies, g=30817, q=1545207 ncpus=2) task:syz.2.166 state:R running task stack:21664 pid:6682 tgid:6682 ppid:6444 flags:0x20004002 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6997 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_count_add+0x121/0x190 kernel/sched/core.c:5778 Code: 0e 00 75 19 90 48 c7 c7 40 59 0a 8c 48 c7 c6 80 59 0a 8c e8 01 a4 f2 ff 90 0f 0b 90 90 90 e9 5c ff ff ff 48 c7 c1 40 f9 3b 9a <80> e1 07 80 c1 03 38 c1 0f 8c fe fe ff ff 48 c7 c7 40 f9 3b 9a e8 RSP: 0018:ffffc90008e27650 EFLAGS: 00000202 RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff9a3bf940 RDX: dffffc0000000000 RSI: ffffffff87f7e58c RDI: 0000000000000001 RBP: ffffc90008e27778 R08: 0000000000000005 R09: ffffc90008e27830 R10: ffffc90008e27790 R11: ffffffff81806870 R12: dffffc0000000000 R13: ffffc90008e27740 R14: ffffffff87f7e58c R15: dffffc0000000000 unwind_next_frame+0xb0/0x22d0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 vfree+0x186/0x2e0 mm/vmalloc.c:3361 vb2_vmalloc_put+0x68/0xb0 drivers/media/common/videobuf2/videobuf2-vmalloc.c:68 __vb2_buf_mem_free+0xfa/0x2a0 drivers/media/common/videobuf2/videobuf2-core.c:275 __vb2_free_mem drivers/media/common/videobuf2/videobuf2-core.c:571 [inline] __vb2_queue_free+0x452/0xb70 drivers/media/common/videobuf2/videobuf2-core.c:599 vb2_core_queue_release+0x6c/0x150 drivers/media/common/videobuf2/videobuf2-core.c:2678 v4l2_m2m_ctx_release+0x2a/0x40 drivers/media/v4l2-core/v4l2-mem2mem.c:1277 vim2m_release+0xd5/0x140 drivers/media/test-drivers/vim2m.c:1245 v4l2_release+0x1f5/0x3b0 drivers/media/v4l2-core/v4l2-dev.c:456 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 __do_fast_syscall_32+0xc4/0x110 arch/x86/entry/common.c:389 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf741d579 RSP: 002b:00000000f756fb1c EFLAGS: 00000206 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 4597 jiffies! g30817 f0x2 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:24912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 5311 Comm: kworker/1:6 Not tainted 6.11.0-syzkaller-10622-gaa486552a110 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:debug_check_no_obj_freed+0x2cc/0x580 lib/debugobjects.c:1019 Code: 00 00 49 89 c4 49 89 c5 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 74 08 4c 89 e7 e8 48 40 3c fd 49 8b 04 24 <48> 89 44 24 38 49 8d 5c 24 18 48 89 d8 48 c1 e8 03 48 b9 00 00 00 RSP: 0018:ffffc90000a17fc0 EFLAGS: 00000046 RAX: ffff8881b7180188 RBX: ffff8881b7180130 RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc90000a17ea0 RBP: ffffc90000a18110 R08: 0000000000000003 R09: fffff52000142fd4 R10: dffffc0000000000 R11: fffff52000142fd4 R12: ffff8881b7180150 R13: 1ffff11036e3002a R14: ffff88821875cd50 R15: 0000000000000023 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f21c7cdf866 CR3: 0000000042aa0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: slab_free_hook mm/slub.c:2274 [inline] slab_free mm/slub.c:4580 [inline] kmem_cache_free+0x11f/0x420 mm/slub.c:4682 nft_synproxy_eval_v4+0x3d2/0x610 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcb/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244