rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5348/1:b..l P5229/1:b..l rcu: (detected by 0, t=10503 jiffies, g=8329, q=1581904 ncpus=2) task:syz-executor state:R running task stack:23680 pid:5229 tgid:5229 ppid:5224 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1893/0x4b50 kernel/sched/core.c:6607 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6786 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6810 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1688 [inline] zap_pmd_range mm/memory.c:1736 [inline] zap_pud_range mm/memory.c:1765 [inline] zap_p4d_range mm/memory.c:1786 [inline] unmap_page_range+0x3818/0x42c0 mm/memory.c:1807 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897 exit_mmap+0x264/0xc80 mm/mmap.c:3412 __mmput+0x115/0x390 kernel/fork.c:1345 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x176f/0x1810 kernel/signal.c:2936 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f030a774157 RSP: 002b:00007ffe2e6d8c20 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 0000000000001488 RCX: 00007f030a774157 RDX: 0000000040000000 RSI: 00007ffe2e6d8c5c RDI: 00000000ffffffff RBP: 00007ffe2e6d8c5c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000000c R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 task:syz.0.15 state:R running task stack:25968 pid:5348 tgid:5345 ppid:5256 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1893/0x4b50 kernel/sched/core.c:6607 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6929 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:lock_acquire+0xc/0x550 kernel/locking/lockdep.c:5790 Code: c0 c3 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 41 57 41 56 <41> 55 41 54 53 48 83 e4 e0 48 81 ec 20 01 00 00 4c 89 4c 24 28 4c RSP: 0018:ffffc90008a77290 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffff88807ac9e010 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e9389e0 RBP: ffffc90008a772a0 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed10037df841 R12: ffffea0001761980 R13: dffffc0000000000 R14: 0000000000000001 R15: ffffffff8205e059 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] percpu_ref_get_many+0x36/0x140 include/linux/percpu-refcount.h:202 percpu_ref_get include/linux/percpu-refcount.h:222 [inline] css_get include/linux/cgroup_refcnt.h:11 [inline] mem_cgroup_commit_charge+0x9f/0x380 mm/memcontrol.c:2389 charge_memcg+0xb1/0x160 mm/memcontrol.c:4442 __mem_cgroup_charge+0x27/0x80 mm/memcontrol.c:4453 mem_cgroup_charge include/linux/memcontrol.h:672 [inline] folio_prealloc+0x52/0x170 mm/memory.c:1068 alloc_anon_folio mm/memory.c:4513 [inline] do_anonymous_page mm/memory.c:4570 [inline] do_pte_missing mm/memory.c:3960 [inline] handle_pte_fault+0x255b/0x7010 mm/memory.c:5536 __handle_mm_fault mm/memory.c:5679 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:5847 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:71 Code: 75 f1 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb c9 a4 c3 cc cc cc cc 48 89 c8 48 c1 e9 03 83 e0 07 f3 48 a5 89 c1 RSP: 0018:ffffc90008a77ad0 EFLAGS: 00050246 RAX: ffffffff84b75201 RBX: 0000000020044040 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffffc90008a77b60 RDI: 0000000020044000 RBP: ffffc90008a77c10 R08: ffffc90008a77b9f R09: 1ffff9200114ef73 R10: dffffc0000000000 R11: fffff5200114ef74 R12: 0000000000000040 R13: 0000000000010580 R14: 0000000020044000 R15: ffffc90008a77b60 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] _inline_copy_to_user include/linux/uaccess.h:181 [inline] _copy_to_user+0x86/0xb0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:209 [inline] rng_dev_read+0x3bb/0x6d0 drivers/char/hw_random/core.c:251 do_loop_readv_writev fs/read_write.c:854 [inline] vfs_readv+0x6bc/0xa80 fs/read_write.c:1027 do_preadv fs/read_write.c:1142 [inline] __do_sys_preadv fs/read_write.c:1192 [inline] __se_sys_preadv fs/read_write.c:1187 [inline] __x64_sys_preadv+0x1c7/0x2d0 fs/read_write.c:1187 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f030a77def9 RSP: 002b:00007f030b59a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007f030a935f80 RCX: 00007f030a77def9 RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000006 RBP: 00007f030a7f0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f030a935f80 R15: 00007f030aa5fa28 rcu: rcu_preempt kthread starved for 9035 jiffies! g8329 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:25712 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1893/0x4b50 kernel/sched/core.c:6607 __schedule_loop kernel/sched/core.c:6684 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6699 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: 5301 Comm: kworker/1:5 Not tainted 6.11.0-syzkaller-07462-g1868f9d0260e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x6f2/0x22d0 arch/x86/kernel/unwind_orc.c:494 Code: b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 48 63 03 48 01 d8 48 8d 4b 04 4c 39 f8 4c 0f 46 f1 48 8d 43 fc 48 0f 47 e8 <4c> 0f 46 e3 49 39 ee 76 a9 e9 55 fb ff ff 89 d9 80 e1 07 80 c1 03 RSP: 0018:ffffc90000a17bb0 EFLAGS: 00000293 RAX: ffffffff90877dec RBX: ffffffff90877df0 RCX: ffffffff90877df4 RDX: 00000000000b0001 RSI: ffffffff9129fc4a RDI: 0000000000000001 RBP: ffffffff90877df0 R08: 0000000000000001 R09: ffffc90000a17d70 R10: ffffc90000a17cd0 R11: ffffffff81807a70 R12: ffffffff90877df0 R13: ffffffff90877df0 R14: ffffffff90877df4 R15: ffffffff8a1a295d FS: 0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005650f2e3e210 CR3: 000000006f72c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x1a1/0x440 mm/slub.c:4728 skb_kfree_head net/core/skbuff.c:1086 [inline] skb_free_head net/core/skbuff.c:1098 [inline] skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb+0x9f/0xf0 net/core/skbuff.c:1436 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