Kernel bug causing speed throttling?

Hardware
1

I have the latest ipFire CU-173 installed on this: Micro Firewall Appliance, Mini PC, VPN, Router PC, Intel N5105, HUNSN RJ03m, AES-NI, 4 x Intel 2.5GbE I226-V LAN. In /var/log/messages I’m seeing a lot of these bug reports.

Operationally, the WAN port on this device is connected to a 300Mbps internet download link. A fresh install of ipFire provides 300Mbps downloads to LAN-port devices for the first several hours. After that, LAN-side devices are only getting ~30Mbps download speeds. Do you think this observed “speed throttling” is due to the bug?

Mar 5 06:57:39 Key-ipFire kernel: ==================================================================
Mar 5 06:57:39 Key-ipFire kernel: BUG: KFENCE: use-after-free read in ipt_do_table+0x17f/0x740
Mar 5 06:57:39 Key-ipFire kernel:
Mar 5 06:57:39 Key-ipFire kernel: Use-after-free read at 0x00000000c0c93a27 (in kfence-#28):
Mar 5 06:57:39 Key-ipFire kernel: ipt_do_table+0x17f/0x740
Mar 5 06:57:39 Key-ipFire kernel: nf_hook_slow+0x3c/0xc0
Mar 5 06:57:39 Key-ipFire kernel: ip_output+0x137/0x180
Mar 5 06:57:39 Key-ipFire kernel: ip_forward+0x40e/0x540
Mar 5 06:57:39 Key-ipFire kernel: ip_sublist_rcv_finish+0x6c/0x80
Mar 5 06:57:39 Key-ipFire kernel: ip_sublist_rcv+0x181/0x210
Mar 5 06:57:39 Key-ipFire kernel: ip_list_rcv+0xf8/0x130
Mar 5 06:57:39 Key-ipFire kernel: __netif_receive_skb_list_core+0x232/0x250
Mar 5 06:57:39 Key-ipFire kernel: netif_receive_skb_list_internal+0x1ab/0x2f0
Mar 5 06:57:39 Key-ipFire kernel: napi_complete_done+0x6f/0x1c0
Mar 5 06:57:39 Key-ipFire kernel: igc_poll+0x6c0/0x1230 [igc]
Mar 5 06:57:39 Key-ipFire kernel: __napi_poll+0x27/0x160
Mar 5 06:57:39 Key-ipFire kernel: net_rx_action+0x2ec/0x580
Mar 5 06:57:39 Key-ipFire kernel: __do_softirq+0xc3/0x282
Mar 5 06:57:39 Key-ipFire kernel: irq_exit_rcu+0x8d/0xb0
Mar 5 06:57:39 Key-ipFire kernel: common_interrupt+0x80/0xa0
Mar 5 06:57:39 Key-ipFire kernel: asm_common_interrupt+0x22/0x40
Mar 5 06:57:39 Key-ipFire kernel: cpuidle_enter_state+0xc7/0x380
Mar 5 06:57:39 Key-ipFire kernel: cpuidle_enter+0x29/0x40
Mar 5 06:57:39 Key-ipFire kernel: do_idle+0x1c3/0x200
Mar 5 06:57:39 Key-ipFire kernel: cpu_startup_entry+0x19/0x20
Mar 5 06:57:39 Key-ipFire kernel: secondary_startup_64_no_verify+0xb0/0xbb
Mar 5 06:57:39 Key-ipFire kernel:
Mar 5 06:57:39 Key-ipFire kernel: kfence-#28: 0x000000002b1ae5cc-0x0000000083537603, size=640, cache=kmalloc-1k
Mar 5 06:57:39 Key-ipFire kernel:
Mar 5 06:57:39 Key-ipFire kernel: allocated by task 0 on cpu 1 at 24977.458152s:
Mar 5 06:57:39 Key-ipFire kernel: __alloc_skb+0x84/0x1d0
Mar 5 06:57:39 Key-ipFire kernel: __napi_alloc_skb+0x3e/0x110
Mar 5 06:57:39 Key-ipFire kernel: igc_poll+0xce5/0x1230 [igc]
Mar 5 06:57:39 Key-ipFire kernel: __napi_poll+0x27/0x160
Mar 5 06:57:39 Key-ipFire kernel: net_rx_action+0x2ec/0x580
Mar 5 06:57:39 Key-ipFire kernel: __do_softirq+0xc3/0x282
Mar 5 06:57:39 Key-ipFire kernel: irq_exit_rcu+0x8d/0xb0
Mar 5 06:57:39 Key-ipFire kernel: common_interrupt+0x80/0xa0
Mar 5 06:57:39 Key-ipFire kernel: asm_common_interrupt+0x22/0x40
Mar 5 06:57:39 Key-ipFire kernel: cpuidle_enter_state+0xc7/0x380
Mar 5 06:57:39 Key-ipFire kernel: cpuidle_enter+0x29/0x40
Mar 5 06:57:39 Key-ipFire kernel: do_idle+0x1c3/0x200
Mar 5 06:57:39 Key-ipFire kernel: cpu_startup_entry+0x19/0x20
Mar 5 06:57:39 Key-ipFire kernel: secondary_startup_64_no_verify+0xb0/0xbb
Mar 5 06:57:39 Key-ipFire kernel:
Mar 5 06:57:39 Key-ipFire kernel: freed by task 0 on cpu 1 at 24977.458175s:
Mar 5 06:57:39 Key-ipFire kernel: pskb_expand_head+0x10f/0x350
Mar 5 06:57:39 Key-ipFire kernel: __pskb_pull_tail+0x52/0x400
Mar 5 06:57:39 Key-ipFire kernel: match+0x146/0x66c [xt_layer7]
Mar 5 06:57:39 Key-ipFire kernel: ipt_do_table+0x2a0/0x740
Mar 5 06:57:39 Key-ipFire kernel: nf_hook_slow+0x3c/0xc0
Mar 5 06:57:39 Key-ipFire kernel: ip_output+0x137/0x180
Mar 5 06:57:39 Key-ipFire kernel: ip_forward+0x40e/0x540
Mar 5 06:57:39 Key-ipFire kernel: ip_sublist_rcv_finish+0x6c/0x80
Mar 5 06:57:39 Key-ipFire kernel: ip_sublist_rcv+0x181/0x210
Mar 5 06:57:39 Key-ipFire kernel: ip_list_rcv+0xf8/0x130
Mar 5 06:57:39 Key-ipFire kernel: __netif_receive_skb_list_core+0x232/0x250
Mar 5 06:57:39 Key-ipFire kernel: netif_receive_skb_list_internal+0x1ab/0x2f0
Mar 5 06:57:39 Key-ipFire kernel: napi_complete_done+0x6f/0x1c0
Mar 5 06:57:39 Key-ipFire kernel: igc_poll+0x6c0/0x1230 [igc]
Mar 5 06:57:39 Key-ipFire kernel: __napi_poll+0x27/0x160
Mar 5 06:57:39 Key-ipFire kernel: net_rx_action+0x2ec/0x580
Mar 5 06:57:39 Key-ipFire kernel: __do_softirq+0xc3/0x282
Mar 5 06:57:39 Key-ipFire kernel: irq_exit_rcu+0x8d/0xb0
Mar 5 06:57:39 Key-ipFire kernel: common_interrupt+0x80/0xa0
Mar 5 06:57:39 Key-ipFire kernel: asm_common_interrupt+0x22/0x40
Mar 5 06:57:39 Key-ipFire kernel: cpuidle_enter_state+0xc7/0x380
Mar 5 06:57:39 Key-ipFire kernel: cpuidle_enter+0x29/0x40
Mar 5 06:57:39 Key-ipFire kernel: do_idle+0x1c3/0x200
Mar 5 06:57:39 Key-ipFire kernel: cpu_startup_entry+0x19/0x20
Mar 5 06:57:39 Key-ipFire kernel: secondary_startup_64_no_verify+0xb0/0xbb
Mar 5 06:57:39 Key-ipFire kernel:
Mar 5 06:57:39 Key-ipFire kernel: CPU: 1 PID: 0 Comm: swapper/1 Tainted: G B 5.15.71-ipfire #1
Mar 5 06:57:39 Key-ipFire kernel: Hardware name: Default string Default string/Default string, BIOS JK4LV105 08/31/2022
Mar 5 06:57:39 Key-ipFire kernel: ==================================================================

Thanks.

2

I am not familiar enough with kernel messages to say that is what is causing the speed throttling but kfence bug messages in IPFire in the past have been related to issues with nic drivers.

https://community.ipfire.org/t/bug-kfence-use-after-free-read-in-ipt-do-t/6888

https://community.ipfire.org/t/core-update-170-bug-kfence-use-after-free-with-rtl-8153-usb-adapter/8623

I also note that you have i226 nics and those have been raised as having issues depending on the ethernet controller being used on the board.

https://community.ipfire.org/t/jetway-fbz10-mini-network-appliance-with-intel-j6412-quad-core-cpu-m-2-2242-and-4x-2-5gb-intel-lan/9359

For more experienced feedback probably need comments from @ms or @arne_f

2 Likes
3

Hello,

I had these types of errors with Realtek RTL 8153 network cards
I had found that they only occur with QoS enabled.
Try disabling it if so.

1 Like
4

Can you set the speed of the NIC to 1 Gbit/sec instead of 2.5 Gbit (maybe in BIOS) and see if the problem still occurs?

2 Likes