rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=f39c/1/0x4000000000000000 softirq=64492/64492 fqs=543 rcu: (detected by 1, t=10502 jiffies, g=111105, q=179 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5052 Comm: syz-fuzzer Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x24/0x60 kernel/kcov.c:207 Code: 00 00 00 00 66 90 f3 0f 1e fa 65 48 8b 14 25 00 bd 03 00 65 8b 05 74 58 7d 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 35 <8b> 82 fc 15 00 00 85 c0 74 2b 8b 82 d8 15 00 00 83 f8 02 75 20 48 RSP: 0018:ffffc90000007470 EFLAGS: 00000002 RAX: 0000000080010101 RBX: ffff8880b982ba40 RCX: ffffffff817519bb RDX: ffff88801f5900c0 RSI: ffffffff81751da8 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000003 R12: ffff8880b982b940 R13: 0000000000000001 R14: ffff8880784c0340 R15: ffffffff88a26490 FS: 0000000001f3c2b0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020266000 CR3: 000000001ca6b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hrtimer_expire_entry include/trace/events/timer.h:239 [inline] __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x9d8/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x105/0x400 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x43/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__sanitizer_cov_trace_pc+0x59/0x60 kernel/kcov.c:225 Code: 82 d8 15 00 00 83 f8 02 75 20 48 8b 8a e0 15 00 00 8b 92 dc 15 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 66 0f 1f 44 00 00 f3 0f 1e fa 41 57 41 56 49 89 d6 41 55 41 54 RSP: 0018:ffffc900000076f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88802a084dc0 RCX: ffffffff88697b9c RDX: ffff88801f5900c0 RSI: ffffffff89524a0d RDI: 0000000000000005 RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000002 R12: ffff88807adaa000 R13: ffff88802a084e98 R14: 0000000000000000 R15: ffff88802a084e30 packet_rcv+0x15d/0x1610 net/packet/af_packet.c:2231 deliver_skb net/core/dev.c:2205 [inline] deliver_ptype_list_skb net/core/dev.c:2220 [inline] __netif_receive_skb_core.constprop.0+0xda9/0x3f50 net/core/dev.c:5483 __netif_receive_skb_list_core+0x343/0x8a0 net/core/dev.c:5608 __netif_receive_skb_list net/core/dev.c:5675 [inline] netif_receive_skb_list_internal+0x769/0xe00 net/core/dev.c:5766 gro_normal_list include/net/gro.h:439 [inline] gro_normal_list include/net/gro.h:435 [inline] napi_complete_done+0x23f/0x990 net/core/dev.c:6106 virtqueue_napi_complete drivers/net/virtio_net.c:440 [inline] virtnet_poll+0xf4a/0x15d0 drivers/net/virtio_net.c:2158 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6536 napi_poll net/core/dev.c:6605 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6738 __do_softirq+0x21a/0x8de kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:247 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:640 RIP: 0010:write_comp_data+0x7e/0x80 kernel/kcov.c:262 Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 90 f3 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 31 ff e9 69 RSP: 0018:ffffc9000332f418 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff8139fcf5 RDX: ffff88801f5900c0 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffffffff8ac9d140 R08: 0000000000000001 R09: 0000000000000004 R10: 0000000000000005 R11: 0000000000000001 R12: 0000000000000005 R13: 0000000000000001 R14: 0000000000000008 R15: ffffc9000332f505 __sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:341 unwind_next_frame+0x6b5/0x2390 arch/x86/kernel/unwind_orc.c:515 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slab.c:3237 [inline] kmem_cache_alloc_node+0x173/0x4a0 mm/slab.c:3509 kmalloc_reserve+0x166/0x260 net/core/skbuff.c:560 __alloc_skb+0x12b/0x330 net/core/skbuff.c:651 alloc_skb_fclone include/linux/skbuff.h:1336 [inline] tcp_stream_alloc_skb+0x34/0x560 net/ipv4/tcp.c:871 tcp_sendmsg_locked+0xeb2/0x3460 net/ipv4/tcp.c:1153 tcp_sendmsg+0x2e/0x40 net/ipv4/tcp.c:1340 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:847 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 sock_write_iter+0x29b/0x3d0 net/socket.c:1158 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x64f/0xdf0 fs/read_write.c:584 ksys_write+0x1f0/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:000000c00152b100 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000040720e RDX: 00000000000000f0 RSI: 000000c0003d4200 RDI: 0000000000000003 RBP: 000000c00152b140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 000000c00152b280 R13: 0000000000000001 R14: 000000c00ebc4000 R15: 000000000000000e rcu: rcu_preempt kthread starved for 7785 jiffies! g111105 f0x0 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:28240 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0xedb/0x5af0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6778 schedule_timeout+0x137/0x290 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1830 kthread+0x2c6/0x3a0 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: 1 PID: 10149 Comm: kworker/u4:20 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:write_comp_data+0x7e/0x80 kernel/kcov.c:262 Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 90 f3 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 31 ff e9 69 RSP: 0018:ffffc90004e77928 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b98414c0 RCX: ffffffff817aada8 RDX: ffff888031596100 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed1017308299 R13: 0000000000000001 R14: ffff8880b98414c8 R15: ffff8880b993d900 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556b74060310 CR3: 000000000cd77000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:311 [inline] smp_call_function_many_cond+0x508/0x1550 kernel/smp.c:855 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2016 [inline] text_poke_bp_batch+0x22b/0x750 arch/x86/kernel/alternative.c:2226 text_poke_flush arch/x86/kernel/alternative.c:2417 [inline] text_poke_flush arch/x86/kernel/alternative.c:2414 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2424 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:830 [inline] toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:822 process_one_work+0x886/0x15d0 kernel/workqueue.c:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2781 kthread+0x2c6/0x3a0 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