rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=b9c4/1/0x4000000000000000 softirq=6260/6262 fqs=4 rcu: (detected by 0, t=10502 jiffies, g=7333, q=68 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5118 Comm: sshd Not tainted 6.9.0-rc6-syzkaller-00234-g7367539ad4b0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:__kasan_check_write+0x0/0x20 mm/kasan/shadow.c:36 Code: 48 8b 0c 24 31 d2 e9 6f e6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 3c e6 ff ff 66 2e RSP: 0018:ffffc90000a08b98 EFLAGS: 00000097 RAX: 0000000000000004 RBX: dffffc0000000000 RCX: 0000000000a08c03 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff88807105d2e8 RBP: ffffc90000a08c80 R08: ffffffff92f355e7 R09: 1ffffffff25e6abc R10: dffffc0000000000 R11: fffffbfff25e6abd R12: ffff88807105d2e8 R13: 1ffff92000141180 R14: ffffc90000a08c00 R15: 1ffff1100e20ba5e FS: 00007f65e68af800(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc197ad018 CR3: 00000000573a0000 CR4: 0000000000350ef0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x142/0x370 kernel/locking/spinlock_debug.c:116 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xab/0xca0 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x5a7/0xd50 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x112/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__rcu_read_lock+0x5/0xb0 kernel/rcu/tree_plugin.h:401 Code: fc ff ff e9 62 fc ff ff e8 48 32 03 0a 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 <41> 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 4c 8b 3c 25 c0 d3 RSP: 0018:ffffc900031f7110 EFLAGS: 00000293 RAX: ffffffff89deccd2 RBX: 0000000000000000 RCX: ffff888029465a00 RDX: 0000000000000000 RSI: ffffffff94aecb00 RDI: 0000000000000004 RBP: ffffc900031f7238 R08: 0000000000000000 R09: ffff888021edc000 R10: dffffc0000000000 R11: fffffbfff1f51f6e R12: 1ffff9200063ee2c R13: ffffffff94aecb00 R14: ffff888022470ff0 R15: dffffc0000000000 rcu_read_lock include/linux/rcupdate.h:779 [inline] nf_hook+0x97/0x450 include/linux/netfilter.h:238 NF_HOOK_COND include/linux/netfilter.h:302 [inline] ip_output+0x185/0x230 net/ipv4/ip_output.c:433 ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x118c/0x1b70 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x2557/0x3b80 net/ipv4/tcp_output.c:1462 tcp_transmit_skb net/ipv4/tcp_output.c:1480 [inline] tcp_write_xmit+0x1445/0x6100 net/ipv4/tcp_output.c:2792 __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:2977 tcp_sendmsg_locked+0x42cc/0x4d00 net/ipv4/tcp.c:1310 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1342 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 sock_write_iter+0x2dd/0x400 net/socket.c:1160 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa86/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f65e6516bf2 Code: 89 c7 48 89 44 24 08 e8 7b 34 fa ff 48 8b 44 24 08 48 83 c4 28 c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6f 48 8b 15 07 a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd643a9c18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000034 RCX: 00007f65e6516bf2 RDX: 0000000000000034 RSI: 000056509ca5f960 RDI: 0000000000000004 RBP: 000056509ca6d220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000056508b938aa4 R13: 0000000000000276 R14: 000056508b9393e8 R15: 00007ffd643a9c88 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 3.166 msecs rcu: rcu_preempt kthread starved for 10494 jiffies! g7333 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:25880 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/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: CPU: 0 PID: 5136 Comm: kworker/u8:1 Not tainted 6.9.0-rc6-syzkaller-00234-g7367539ad4b0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1899/0x2a00 kernel/smp.c:855 Code: 89 e6 83 e6 01 31 ff e8 15 db 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c0 d6 0b 00 eb 38 f3 90 42 0f b6 04 23 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 a4 d6 0b 00 eb e4 44 RSP: 0018:ffffc90004b1f6e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110172a8869 RCX: ffff8880295c9e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004b1f8e0 R08: ffffffff818a39eb R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: dffffc0000000000 R13: ffff8880b9544348 R14: ffff8880b943f7c0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5fa233e120 CR3: 000000000e134000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2086 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2296 text_poke_flush arch/x86/kernel/alternative.c:2487 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2494 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:826 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3348 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244