rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5337/1:b..l P5221/1:b..l rcu: (detected by 1, t=10502 jiffies, g=6297, q=3826833 ncpus=2) task:syz-executor state:R running task stack:23072 pid:5221 tgid:5221 ppid:5216 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6854 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6878 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:1691 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0x36b1/0x40e0 mm/memory.c:1810 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1900 exit_mmap+0x275/0xc40 mm/mmap.c:1864 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 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: 0033:0x7f27cc974213 RSP: 002b:00007ffe0e7f9048 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000000000000146a RCX: 00007f27cc974213 RDX: 0000000040000000 RSI: 00007ffe0e7f905c RDI: 00000000ffffffff RBP: 00007ffe0e7f905c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000c R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 task:syz.2.3 state:R running task stack:23888 pid:5337 tgid:5336 ppid:5232 flags:0x00004006 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:bytes_is_nonzero mm/kasan/generic.c:87 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x86/0x290 mm/kasan/generic.c:189 Code: 00 fc ff df 4f 8d 3c 31 4c 89 fd 4c 29 dd 48 83 fd 10 7f 29 48 85 ed 0f 84 3e 01 00 00 4c 89 cd 48 f7 d5 48 01 dd 41 80 3b 00 <0f> 85 c9 01 00 00 49 ff c3 48 ff c5 75 ee e9 1e 01 00 00 45 89 dc RSP: 0018:ffffc900043574c0 EFLAGS: 00000246 RAX: ffffffff82092401 RBX: 1ffff11003dccd74 RCX: ffffffff82092452 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88801ee66ba0 RBP: ffffffffffffffff R08: ffff88801ee66ba7 R09: 1ffff11003dccd74 R10: dffffc0000000000 R11: ffffed1003dccd74 R12: 0000000000000002 R13: dffffc0000000000 R14: dffffc0000000001 R15: ffffed1003dccd75 instrument_write include/linux/instrumented.h:40 [inline] ___clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:44 [inline] __update_page_owner_free_handle mm/page_owner.c:272 [inline] __reset_page_owner+0x152/0x430 mm/page_owner.c:298 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 discard_slab mm/slub.c:2678 [inline] __put_partials+0xeb/0x130 mm/slub.c:3146 put_cpu_partial+0x17c/0x250 mm/slub.c:3221 __slab_free+0x2ea/0x3d0 mm/slub.c:4450 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142 rxrpc_alloc_call+0x27a/0xdd0 net/rxrpc/call_object.c:128 rxrpc_service_prealloc_one+0x35b/0xd70 net/rxrpc/call_accept.c:98 rxrpc_kernel_charge_accept+0xd2/0x100 net/rxrpc/call_accept.c:475 afs_charge_preallocation+0xba/0x2c0 fs/afs/rxrpc.c:712 afs_open_socket+0x459/0x610 fs/afs/rxrpc.c:94 afs_net_init+0x7b9/0x9a0 fs/afs/main.c:123 ops_init+0x31e/0x590 net/core/net_namespace.c:139 setup_net+0x287/0x9e0 net/core/net_namespace.c:356 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:494 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228 ksys_unshare+0x619/0xc10 kernel/fork.c:3315 __do_sys_unshare kernel/fork.c:3386 [inline] __se_sys_unshare kernel/fork.c:3384 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3384 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: 0033:0x7fc99997dff9 RSP: 002b:00007fc99a6ce038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007fc999b35f80 RCX: 00007fc99997dff9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000068060200 RBP: 00007fc9999f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc999b35f80 R15: 00007fff8d0e23d8 rcu: rcu_preempt kthread starved for 10459 jiffies! g6297 f0x2 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:25136 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc1-syzkaller-00238-g8b641b5e4c78 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:lockdep_hardirqs_on_prepare+0xee/0x780 kernel/locking/lockdep.c:4387 Code: 03 0f b6 04 10 84 c0 0f 85 33 05 00 00 83 3d 78 c0 cc 18 00 0f 85 a8 00 00 00 4c 8d 74 24 40 4c 89 f3 48 c1 eb 03 80 3c 13 00 <74> 12 4c 89 f7 e8 f8 84 8e 00 48 ba 00 00 00 00 00 fc ff df 48 c7 RSP: 0018:ffffc900001565c0 EFLAGS: 00000046 RAX: 0000000000000004 RBX: 1ffff9200002acc0 RCX: ffffffff9a3cc903 RDX: dffffc0000000000 RSI: ffffffff8c60f840 RDI: ffffffff8c60f800 RBP: ffffc90000156668 R08: ffffffff901ce76f R09: 1ffffffff2039ced R10: dffffc0000000000 R11: fffffbfff2039cee R12: ffffffff818283d3 R13: 0000000000000200 R14: ffffc90000156600 R15: 1ffff9200002acbc FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0a42772866 CR3: 000000002848e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61 native_save_fl arch/x86/include/asm/irqflags.h:19 [inline] arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] arch_irqs_disabled arch/x86/include/asm/irqflags.h:147 [inline] seqcount_lockdep_reader_access+0x157/0x220 include/linux/seqlock.h:74 ktime_get_with_offset+0x83/0x150 kernel/time/timekeeping.c:891 ktime_get_real include/linux/timekeeping.h:82 [inline] netif_rx_internal+0x459/0x630 net/core/dev.c:5172 __netif_rx+0x78/0xc0 net/core/dev.c:5215 loopback_xmit+0x454/0x6b0 drivers/net/loopback.c:89 __netdev_start_xmit include/linux/netdevice.h:4920 [inline] netdev_start_xmit include/linux/netdevice.h:4929 [inline] xmit_one net/core/dev.c:3588 [inline] dev_hard_start_xmit+0x27a/0x7e0 net/core/dev.c:3604 __dev_queue_xmit+0x1b11/0x3ed0 net/core/dev.c:4428 dev_queue_xmit include/linux/netdevice.h:3098 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 synproxy_send_client_synack+0x8b8/0xf30 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 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:5666 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5779 process_backlog+0x662/0x15b0 net/core/dev.c:6111 __napi_poll+0xcb/0x490 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6966 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 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