Created attachment 256665 [details]
dmesg output

Confirming with v4.11.x (checked with .0 and .2).

If it helps, here is what was altered in sysctl by me:

===
» cat /etc/sysctl.d/*
net.ipv4.ip_nonlocal_bind = 1
net.ipv4.ip_local_port_range = 1026 59999
net.ipv4.ip_forward = 1
net.ipv6.conf.all.forwarding = 1
net.ipv6.route.max_size = 16384
net.ipv4.ip_dynaddr = 1
net.ipv4.tcp_mtu_probing = 1
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_congestion_control = bbr
net.ipv4.tcp_fastopen = 3
net.ipv4.tcp_low_latency = 1
net.ipv4.tcp_fin_timeout = 10
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_slow_start_after_idle = 0
net.ipv4.tcp_rmem = 4096 262143 4194304
net.ipv4.tcp_wmem = 4096 262143 4194304
net.ipv4.tcp_keepalive_time = 300
net.ipv4.tcp_keepalive_intvl = 60
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_fin_timeout = 10
net.ipv4.tcp_retries2 = 5
net.core.rmem_max = 4194304
net.core.rmem_default = 262143
net.core.wmem_max = 4194304
net.core.wmem_default = 262143
net.core.bpf_jit_enable = 1
net.ipv4.tcp_ecn = 1
vm.min_free_kbytes = 131072
===

Since this bug is still present in 4.11.5 I figure I'll help with the bug reporting.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 373 at net/ipv4/tcp_input.c:2820 tcp_fastretrans_alert+0x83f/0xa80
Modules linked in: ip6table_nat nf_nat_ipv6 ip6t_REJECT nf_reject_ipv6 ip6table_mangle xt_recent ipt_REJECT nf_reject_ipv4 xt_comment xt_hashlimit xt_addrtype xt_mark xt_nat ip6table_raw xt_multiport nf_conntrack_ipv6
 iptable_mangle iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c crc32c_generic btrfs xor adt7475 hwmon_vid gpio_ich iTCO_wdt evdev iTCO_vendor_support mac_hid raid6_pq nouveau psm
CPU: 0 PID: 373 Comm: irq/19-enp5s4 Not tainted 4.11.5-2-ck-core2 #1
Hardware name: System manufacturer System Product Name/P5B-Deluxe, BIOS 1238    09/30/2008
Call Trace:
 <IRQ>
 dump_stack+0x63/0x81
 __warn+0xcb/0xf0
 warn_slowpath_null+0x1d/0x20
 tcp_fastretrans_alert+0x83f/0xa80
 tcp_ack+0xdbd/0x1450
 tcp_rcv_established+0x137/0x700
 ? sk_filter_trim_cap+0x7e/0x280
 tcp_v4_do_rcv+0x11d/0x220
 tcp_v4_rcv+0x9aa/0xd20
 ip_local_deliver_finish+0x68/0x200
 ip_local_deliver+0x5c/0x110
 ? inet_del_offload+0x40/0x40
 ip_rcv_finish+0x227/0x400
 ip_rcv+0x258/0x3b0
 ? ip_local_deliver_finish+0x200/0x200
 __netif_receive_skb_core+0x3b6/0xaa0
 ? tcp4_gro_receive+0xf3/0x1d0
 __netif_receive_skb+0x18/0x60
 netif_receive_skb_internal+0x81/0xd0
 napi_gro_receive+0x124/0x160
 skge_poll+0x3c9/0x8d0 [skge]
 net_rx_action+0x12c/0x3a0
 __do_softirq+0xd1/0x317
 ? irq_finalize_oneshot.part.2+0xe0/0xe0
 do_softirq_own_stack+0x1c/0x30
 </IRQ>
 do_softirq.part.4+0x4e/0x50
 __local_bh_enable_ip+0x88/0xa0
 irq_forced_thread_fn+0x59/0x70
 irq_thread+0x12f/0x1c0
 ? wake_threads_waitq+0x30/0x30
 kthread+0x124/0x140
 ? irq_thread_dtor+0xc0/0xc0
 ? kthread_create_on_node+0x70/0x70
 ret_from_fork+0x2c/0x40
---[ end trace 626ef6824790ee27 ]---

And this is what's in my sysctl:
vm.dirty_ratio=40
vm.swappiness=10
net.ipv4.tcp_fin_timeout=15
net.ipv4.tcp_timestamps=1
net.ipv4.tcp_no_metrics_save=1
net.ipv4.tcp_rfc1337=1
net.ipv4.tcp_max_tw_buckets=1440000
net.ipv4.tcp_max_syn_backlog=8096
net.ipv4.tcp_wmem=4096 524288 11960320
net.ipv4.tcp_rmem=4096 524288 11960320
net.ipv4.tcp_mtu_probing=1
net.ipv4.tcp_ecn=1
net.ipv4.tcp_slow_start_after_idle=0
net.ipv4.tcp_tw_reuse=1
net.core.netdev_max_backlog=5000
net.core.somaxconn=1000
net.core.optmem_max=25165824
net.core.rmem_default=262144
net.core.wmem_default=262144
net.core.rmem_max=11960320
net.core.wmem_max=11960320
net.ipv4.udp_rmem_min=8192
net.ipv4.udp_wmem_min=8192
net.ipv4.tcp_synack_retries=2
fs.inotify.max_user_watches = 100000

same problem on 4.11.8

 1441.130236] WARNING: CPU: 0 PID: 0 at net/ipv4/tcp_input.c:2820 tcp_fastretrans_alert+0x8db/0xac0
[ 1441.130388] Modules linked in: netconsole veth ccm sch_pie sctp act_mirred ifb sch_ingress nf_conntrack_netlink nfnetlink cls_u32 sch_sfq sch_htb sit tunnel4 ip_tunnel nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6table_raw ip6_tables iptable_raw ipt_MASQUERADE nf_nat_masquerade_ipv4 xt_nat iptable_nat nf_nat_ipv4 nf_nat xt_TCPMSS xt_sctp ipt_REJECT nf_reject_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 xt_tcpudp xt_recent xt_conntrack nf_conntrack xt_multiport iptable_filter iptable_mangle ip_tables x_tables radeon ath9k led_class ath9k_common ath9k_hw i2c_algo_bit ttm drm_kms_helper mac80211 sch_fq_codel ath cfbfillrect cfg80211 syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea drm br_netfilter bridge snd_hda_codec_via snd_hda_codec_generic snd_hda_intel snd_hda_codec stp backlight
[ 1441.131643]  llc rfkill r8169 xhci_pci snd_usb_audio snd_hwdep snd_usbmidi_lib snd_hda_core snd_rawmidi ohci_pci xhci_hcd snd_seq_device ohci_hcd parport_pc vhost_net snd_pcm i2c_piix4 snd_timer tun mii btrfs acpi_cpufreq button asus_atk0110 snd soundcore vhost processor tap xor kvm_amd kvm irqbypass gspca_zc3xx gspca_main v4l2_common k10temp hwmon raid6_pq uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videodev videobuf2_core i2c_core parport fbcon nfsd auth_rpcgss oid_registry nfs_acl bitblit lockd softcursor fb grace sunrpc fbdev font ipv6 autofs4
[ 1441.148700] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.8 #5
[ 1441.152945] Hardware name: System manufacturer System Product Name/M4A77TD, BIOS 2104    06/28/2010
[ 1441.157251] Call Trace:
[ 1441.161496]  <IRQ>
[ 1441.165683]  ? dump_stack+0x46/0x6d
[ 1441.169853]  ? __warn+0xb4/0xe0
[ 1441.174022]  ? tcp_fastretrans_alert+0x8db/0xac0
[ 1441.178238]  ? tcp_ack+0xd58/0x1300
[ 1441.182411]  ? tcp_rcv_established+0xf4/0x6a0
[ 1441.186550]  ? tcp_v4_do_rcv+0x115/0x200
[ 1441.190633]  ? tcp_v4_rcv+0xaef/0xb80
[ 1441.194722]  ? nf_nat_ipv4_fn+0x53/0x1a0 [nf_nat_ipv4]
[ 1441.198818]  ? ip_local_deliver_finish+0x87/0x1e0
[ 1441.202898]  ? ip_local_deliver+0x3d/0xc0
[ 1441.206960]  ? inet_del_offload+0x40/0x40
[ 1441.211011]  ? ip_rcv+0x281/0x380
[ 1441.215058]  ? ip_local_deliver_finish+0x1e0/0x1e0
[ 1441.219141]  ? __netif_receive_skb_core+0x49b/0x9c0
[ 1441.223230]  ? netif_receive_skb_internal+0x1a/0x80
[ 1441.227307]  ? ifb_ri_tasklet+0x16a/0x240 [ifb]
[ 1441.231361]  ? tasklet_action+0x8c/0xa0
[ 1441.235395]  ? __do_softirq+0xd4/0x200
[ 1441.239428]  ? irq_exit+0xe7/0x100
[ 1441.243450]  ? do_IRQ+0x45/0xc0
[ 1441.247472]  ? common_interrupt+0x89/0x89
[ 1441.251506]  </IRQ>
[ 1441.255512]  ? amd_e400_idle+0x1a/0x40
[ 1441.259503]  ? amd_e400_idle+0x18/0x40
[ 1441.263451]  ? do_idle+0x159/0x1a0
[ 1441.267373]  ? cpu_startup_entry+0x58/0x60
[ 1441.271340]  ? start_kernel+0x3d4/0x3dc
[ 1441.275331]  ? start_cpu+0x14/0x14
[ 1441.279504] ---[ end trace fa5d523840b633b2 ]---

sysctl ip related:

net.netfilter.nf_conntrack_tcp_timeout_established = 6000
net.core.rmem_max = 134217728
net.core.rmem_max = 134217728
net.core.optmem_max = 25165824
net.ipv4.tcp_rmem = 4096 87380 67108864
net.ipv4.tcp_wmem = 4096 65536 67108864
net.ipv4.udp_mem = 4096 65536 67108864
net.core.netdev_max_backlog = 250000
net.core.somaxconn = 32000
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_sack = 1
net.ipv4.tcp_fack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_max_syn_backlog = 65535
net.ipv4.tcp_max_tw_buckets = 1440000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout = 15
net.ipv4.tcp_keepalive_time = 300
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl = 20
net.ipv4.tcp_fastopen = 1
net.ipv4.tcp_mtu_probing = 1
net.ipv4.tcp_rfc1337 = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_syn_retries = 2
net.ipv4.tcp_synack_retries = 2
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.conf.all.force_igmp_version = 0
net.ipv4.conf.all.accept_redirects = 1
net.ipv4.conf.all.secure_redirects = 1
net.ipv4.conf.eth_net.accept_redirects = 0
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.conf.default.rp_filter = 0
net.ipv4.conf.all.rp_filter = 0
net.ipv4.conf.eth_net.rp_filter = 1
net.ipv4.ip_forward = 1

Same with v4.12.

I too am seeing this on Fedora 26:4.11.11-300.fc26.x86_64

Is there a workaround for this, or is it mostly harmless?

Thanks!

(In reply to Bryan Seitz from comment #6)
> I too am seeing this on Fedora 26:4.11.11-300.fc26.x86_64
> 
> Is there a workaround for this, or is it mostly harmless?
> 
> Thanks!

It causes my system to hang after 10+ hours or so. The only way to avoid it is to either not run Transmission at all or to use an older kernel, like 4.9.

Anyone know if this will ever be fixed???

Bugzilla is not used directly for tracking Linux networking bugs.
Bugs reported here are forwarded onto netdev@vger.kernel.org