Netgear R7800 17.01.4 Kernel Warnings

I've been running 17.01.4 for a couple weeks now, and I'm seeing occasional kernel warning/stack backtraces, plus a hang/reboot/something weird just now while doing a large download (internet->wifi client). The download is restarted and running now, but I'm seeing warnings like this:

Sun Mar  4 11:31:26 2018 kern.warn kernel: [ 2007.521605] ------------[ cut here ]------------
Sun Mar  4 11:31:26 2018 kern.warn kernel: [ 2007.528283] WARNING: CPU: 0 PID: 3 at net/sched/sch_hfsc.c:1426 hfsc_dequeue+0x188/0x568 [sch_hfsc]()
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.533013] Modules linked in: ifb pppoe ppp_async iptable_nat pppox ppp_generic nf_nat_ipv4 nf_conntrack_ipv6 nf_conntrack_ipv4 ipt_REJECT ipt_MASQUERADE xt_time xt_tcpudp xt_tcpmss xt_statistic xt_state xt_recent xt_nat xt_multiport xt_mark xt_mac xt_limit xt_length xt_hl xt_helper xt_ecn xt_dscp xt_conntrack xt_connmark xt_connlimit xt_connbytes xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_HL xt_DSCP xt_CLASSIFY usblp ums_usbat ums_sddr55 ums_sddr09 ums_karma Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.656877] CPU: 0 PID: 3 Comm: ksoftirqd/0 Tainted: G        W       4.4.92 #0
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.656968] Hardware name: Qualcomm (Flattened Device Tree)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.664105] [<c02207c4>] (unwind_backtrace) from [<c021d258>] (show_stack+0x14/0x20)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.669657] [<c021d258>] (show_stack) from [<c03bd380>] (dump_stack+0x8c/0xa0)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.677642] [<c03bd380>] (dump_stack) from [<c0228b88>] (warn_slowpath_common+0xa4/0xd0)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.684669] [<c0228b88>] (warn_slowpath_common) from [<c0228c68>] (warn_slowpath_null+0x1c/0x24)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.692930] [<c0228c68>] (warn_slowpath_null) from [<bf282490>] (hfsc_dequeue+0x188/0x568 [sch_hfsc])
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.701702] [<bf282490>] (hfsc_dequeue [sch_hfsc]) from [<c0532950>] (__qdisc_run+0xcc/0x1b4)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.710800] [<c0532950>] (__qdisc_run) from [<c0510120>] (net_tx_action+0xf4/0x180)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.719306] [<c0510120>] (net_tx_action) from [<c022bd84>] (__do_softirq+0xdc/0x230)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.726769] [<c022bd84>] (__do_softirq) from [<c022bf0c>] (run_ksoftirqd+0x34/0x64)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.734758] [<c022bf0c>] (run_ksoftirqd) from [<c024698c>] (smpboot_thread_fn+0x190/0x1b8)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.742139] [<c024698c>] (smpboot_thread_fn) from [<c0243aec>] (kthread+0xf8/0x100)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.750469] [<c0243aec>] (kthread) from [<c0209cb8>] (ret_from_fork+0x14/0x3c)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.758096] ---[ end trace 70b2df21d1202634 ]---
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.766032] ath10k_pci 0001:01:00.0: SWBA overrun on vdev 0, skipped old beacon
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.770182] ath10k_pci 0001:01:00.0: SWBA overrun on vdev 1, skipped old beacon
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.777134] ath10k_pci 0001:01:00.0: SWBA overrun on vdev 0, skipped old beacon
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.784525] ath10k_pci 0001:01:00.0: SWBA overrun on vdev 1, skipped old beacon
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.791795] ath10k_pci 0001:01:00.0: SWBA overrun on vdev 0, skipped old beacon
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.799118] ath10k_pci 0001:01:00.0: SWBA overrun on vdev 1, skipped old beacon
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.806299] ath10k_pci 0001:01:00.0: SWBA overrun on vdev 0, skipped old beacon
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.813671] ath10k_pci 0001:01:00.0: SWBA overrun on vdev 1, skipped old beacon
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.821255] ------------[ cut here ]------------
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.828279] WARNING: CPU: 1 PID: 2387 at net/sched/sch_hfsc.c:1426 hfsc_dequeue+0x188/0x568 [sch_hfsc]()
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.833017] Modules linked in: ifb pppoe ppp_async iptable_nat pppox ppp_generic nf_nat_ipv4 nf_conntrack_ipv6 nf_conntrack_ipv4 ipt_REJECT ipt_MASQUERADE xt_time xt_tcpudp xt_tcpmss xt_statistic xt_state xt_recent xt_nat xt_multiport xt_mark xt_mac xt_limit xt_length xt_hl xt_helper xt_ecn xt_dscp xt_conntrack xt_connmark xt_connlimit xt_connbytes xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_HL xt_DSCP xt_CLASSIFY usblp ums_usbat ums_sddr55 ums_sddr09 ums_karma Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.957144] CPU: 1 PID: 2387 Comm: logread Tainted: G        W       4.4.92 #0
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.957232] Hardware name: Qualcomm (Flattened Device Tree)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.964371] [<c02207c4>] (unwind_backtrace) from [<c021d258>] (show_stack+0x14/0x20)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.969840] [<c021d258>] (show_stack) from [<c03bd380>] (dump_stack+0x8c/0xa0)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.977823] [<c03bd380>] (dump_stack) from [<c0228b88>] (warn_slowpath_common+0xa4/0xd0)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.984850] [<c0228b88>] (warn_slowpath_common) from [<c0228c68>] (warn_slowpath_null+0x1c/0x24)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2007.993114] [<c0228c68>] (warn_slowpath_null) from [<bf282490>] (hfsc_dequeue+0x188/0x568 [sch_hfsc])
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.001889] [<bf282490>] (hfsc_dequeue [sch_hfsc]) from [<c0532950>] (__qdisc_run+0xcc/0x1b4)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.010985] [<c0532950>] (__qdisc_run) from [<c0514e6c>] (__dev_queue_xmit+0x30c/0x56c)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.019493] [<c0514e6c>] (__dev_queue_xmit) from [<bf2b071c>] (tcf_mirred+0x1a4/0x1ec [act_mirred])
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.027320] [<bf2b071c>] (tcf_mirred [act_mirred]) from [<c0538918>] (tcf_action_exec+0x60/0x98)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.036338] [<c0538918>] (tcf_action_exec) from [<bf2a8500>] (u32_classify+0x194/0x380 [cls_u32])
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.045370] [<bf2a8500>] (u32_classify [cls_u32]) from [<c05341c4>] (tc_classify+0x74/0x12c)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.054121] [<c05341c4>] (tc_classify) from [<c050f8b8>] (__netif_receive_skb_core+0x38c/0x99c)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.062626] [<c050f8b8>] (__netif_receive_skb_core) from [<c0512e3c>] (process_backlog+0xa0/0x168)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.071046] [<c0512e3c>] (process_backlog) from [<c051256c>] (net_rx_action+0x128/0x2e4)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.080077] [<c051256c>] (net_rx_action) from [<c022bd84>] (__do_softirq+0xdc/0x230)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.088321] [<c022bd84>] (__do_softirq) from [<c022c1d8>] (irq_exit+0xb0/0x140)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.096049] [<c022c1d8>] (irq_exit) from [<c021f9f8>] (handle_IPI+0xd4/0x1bc)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.103078] [<c021f9f8>] (handle_IPI) from [<c0209474>] (gic_handle_irq+0x90/0xbc)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.110369] [<c0209474>] (gic_handle_irq) from [<c020a594>] (__irq_svc+0x54/0x70)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.117824] Exception stack(0xd9677e60 to 0xd9677ea8)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.125396] 7e60: d9677ed0 b6fee000 00000000 00001000 dcb26e70 b6fed000 00003000 dcb26ed8
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.130432] 7e80: db3a5a40 00100000 c07cc610 00000000 00001000 d9677eb4 b6f48000 c02c772c
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.138575] 7ea0: a0000013 ffffffff
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.146741] [<c020a594>] (__irq_svc) from [<c02c772c>] (unmapped_area_topdown+0xb4/0x1a0)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.150041] [<c02c772c>] (unmapped_area_topdown) from [<c02235cc>] (arch_get_unmapped_area_topdown+0x78/0x134)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.158374] [<c02235cc>] (arch_get_unmapped_area_topdown) from [<c02c5fd8>] (get_unmapped_area.part.1+0x58/0xa8)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.168272] [<c02c5fd8>] (get_unmapped_area.part.1) from [<c02c8c9c>] (do_mmap+0x130/0x3d8)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.178602] [<c02c8c9c>] (do_mmap) from [<c02b83b4>] (vm_mmap_pgoff+0x78/0xbc)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.186672] [<c02b83b4>] (vm_mmap_pgoff) from [<c02c7194>] (SyS_mmap_pgoff+0x94/0xf0)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.193962] [<c02c7194>] (SyS_mmap_pgoff) from [<c0209c00>] (ret_fast_syscall+0x0/0x3c)
Sun Mar  4 11:31:27 2018 kern.warn kernel: [ 2008.201955] ---[ end trace 70b2df21d1202635 ]---

Any pointers to where to begin looking? Or is this sort of warning expected and handled correctly, so there's nothing that needs fixing?

This might be an issue with SQM. See this bug report.

Thanks, I'll poke around there!