lan78xx_get_link_ksettings Oops when using bridging on Raspberry Pi 3 B+

[Ryan Finnie]

When trying to bridge lan78xx eth0 to a bridge on Raspberry Pi 3 B+, an Oops is generated and all interactions with eth0 deadlock. It appears to be the same as https://github.com/raspberrypi/linux/issues/2442 (patch at https://github.com/raspberrypi/linux/commit/c445a42487ff862a352911f485b8d3c45744edf0).

[ 17.172107] brcmfmac: brcmf_sdio_htclk: HT Avail timeout (1000000): clkctl 0x50
[ 17.191290] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[ 17.202764] Unable to handle kernel NULL pointer dereference at virtual address 00000220
[ 17.202772] pgd = ff8acf62
[ 17.202775] [00000220] *pgd=00000000
[ 17.202786] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
[ 17.202791] Modules linked in: bridge stp llc btsdio(+) bluetooth ecdh_generic brcmfmac brcmutil microchip cfg80211 joydev lan78xx uio_pdrv_genirq uio sch_fq_codel iscsi_tcp libiscsi_tcp libiscsi ip_tables x_tables btrfs zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor xor_neon raid6_pq raid1 raid0 multipath linear uas crc32_arm_ce sdhci_iproc aes_arm_bs crypto_simd cryptd
[ 17.202882] CPU: 2 PID: 1133 Comm: brctl Not tainted 4.15.0-1010-raspi2 #11-Ubuntu
[ 17.202884] Hardware name: BCM2835
[ 17.202900] PC is at phy_ethtool_ksettings_get+0x1c/0x94
[ 17.202919] LR is at lan78xx_get_link_ksettings+0x3c/0x4c [lan78xx]
[ 17.202922] pc : [<8071b700>] lr : [<7f3deec8>] psr: 600f0013
[ 17.202925] sp : b0a77cd8 ip : b0a77cf0 fp : b0a77cec
[ 17.202928] r10: b51b6fe0 r9 : 8102cba0 r8 : b6686400
[ 17.202931] r7 : b0a77d64 r6 : 00000000 r5 : 00000000 r4 : b0a77d64
[ 17.202934] r3 : b552c5ac r2 : 00000001 r1 : b0a77d64 r0 : 00000000
[ 17.202940] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
[ 17.202942] Control: 10c5383d Table: 30a7806a DAC: 00000051
[ 17.202946] Process brctl (pid: 1133, stack limit = 0x6c3d92c5)
[ 17.202949] Stack: (0xb0a77cd8 to 0xb0a78000)
[ 17.202958] 7cc0: b56d9000 00000000
[ 17.202968] 7ce0: b0a77d0c b0a77cf0 7f3deec8 8071b6f0 80f05dc8 b56d9000 b0a77d64 00000000
[ 17.202974] 7d00: b0a77d5c b0a77d10 8089ab04 7f3dee98 b0a77d44 b0a77d20 80320e58 809ee454
[ 17.202980] 7d20: b52dd0b8 b52fcb28 afd16bc0 b52fc198 00000001 b0a77e68 b0a77d64 889f956e
[ 17.202988] 7d40: 80387378 80f05dc8 b56d9000 b9e04580 b0a77dc4 b0a77d60 7f884f94 8089aa40
[ 17.202993] 7d60: 8038f2f0 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 17.202998] 7d80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 17.203004] 7da0: 00000000 00000000 00000000 889f956e b56d9000 00000001 b0a77df4 b0a77dc8
[ 17.203013] 7dc0: 7f885900 7f884f6c b0a77de4 b0a77dd8 80f81200 b9e04580 00000002 00000001
[ 17.203020] 7de0: 7f89a0c4 00000000 b0a77e14 b0a77df8 7f88697c 7f885718 b0a77e7c 000089a2
[ 17.203026] 7e00: b9e04000 b0a77e7c b0a77e2c b0a77e18 7f887460 7f88691c 80f05dc8 000089a2
[ 17.203031] 7e20: b0a77e64 b0a77e30 808b6d08 7f887400 80889e58 808b6f20 b0a77e7c 889f956e
[ 17.203041] 7e40: 80f81200 000089a2 80f05dc8 7eb889ac 00000000 00000000 b0a77ecc b0a77e68
[ 17.203055] 7e60: 808b73b4 808b6b84 000089a2 00000000 7eb889ac 00000000 000000cc 00307262
[ 17.203060] 7e80: 00000000 00000000 00000000 00000002 00509d4c 00000002 7eb88ca3 889f956e
[ 17.203066] 7ea0: 00000000 000089a2 fffffdfd 7eb889ac 80f81200 80f05dc8 7eb889ac b51b6fe0
[ 17.203071] 7ec0: b0a77eec b0a77ed0 8086d984 808b6f8c b5668780 00000003 00000000 000089a2
[ 17.203078] 7ee0: b0a77f7c b0a77ef0 8031b578 8086d87c b52fcee0 b9eb0310 b0a77f14 b0a77f08
[ 17.203084] 7f00: 8032bb48 8032b934 b0a77f54 b0a77f18 80307914 8032bb20 00000020 00000000
[ 17.203089] 7f20: 8014e3a8 b9f94264 b9f94240 00000000 b9f94240 b9f93d00 80fb5230 b9f94264
[ 17.203095] 7f40: 00000000 889f956e ffffe000 889f956e 00000002 b5668780 b5668780 00000000
[ 17.203100] 7f60: 000089a2 7eb889ac 00000003 00000080 b0a77fa4 b0a77f80 8031be04 8031b4c4
[ 17.203105] 7f80: 0050a008 76f99968 00000002 00000036 80109284 b0a76000 00000000 b0a77fa8
[ 17.203111] 7fa0: 8010924c 8031bd9c 0050a008 76f99968 00000003 000089a2 7eb889ac 000000cc
[ 17.203116] 7fc0: 0050a008 76f99968 00000002 00000036 7eb88ca9 00000000 00509f1c 00000000
[ 17.203122] 7fe0: 00509f64 7eb88994 004f80cd 76f0c0a8 a00f0030 00000003 55555555 55555555
[ 17.203153] [<8071b700>] (phy_ethtool_ksettings_get) from [<7f3deec8>] (lan78xx_get_link_ksettings+0x3c/0x4c [lan78xx])
[ 17.203195] [<7f3deec8>] (lan78xx_get_link_ksettings [lan78xx]) from [<8089ab04>] (__ethtool_get_link_ksettings+0xd0/0x104)
[ 17.203256] [<8089ab04>] (__ethtool_get_link_ksettings) from [<7f884f94>] (port_cost+0x34/0xa0 [bridge])
[ 17.203329] [<7f884f94>] (port_cost [bridge]) from [<7f885900>] (br_add_if+0x1f4/0x630 [bridge])
[ 17.203391] [<7f885900>] (br_add_if [bridge]) from [<7f88697c>] (add_del_if+0x6c/0x80 [bridge])
[ 17.203456] [<7f88697c>] (add_del_if [bridge]) from [<7f887460>] (br_dev_ioctl+0x6c/0x94 [bridge])
[ 17.203501] [<7f887460>] (br_dev_ioctl [bridge]) from [<808b6d08>] (dev_ifsioc+0x190/0x374)
[ 17.203514] [<808b6d08>] (dev_ifsioc) from [<808b73b4>] (dev_ioctl+0x434/0x968)
[ 17.203525] [<808b73b4>] (dev_ioctl) from [<8086d984>] (sock_ioctl+0x114/0x30c)
[ 17.203541] [<8086d984>] (sock_ioctl) from [<8031b578>] (do_vfs_ioctl+0xc0/0x8d8)
[ 17.203552] [<8031b578>] (do_vfs_ioctl) from [<8031be04>] (SyS_ioctl+0x74/0x84)
[ 17.203565] [<8031be04>] (SyS_ioctl) from [<8010924c>] (__sys_trace_return+0x0/0x10)
[ 17.203574] Code: e52de004 e8bd4000 e1a04001 e1a05000 (e5901220)
[ 17.203621] ---[ end trace 6667b15675c497ef ]---
[ 18.179172] brcmfmac: brcmf_sdio_htclk: HT Avail timeout (1000000): clkctl 0x50

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-1010-raspi2 4.15.0-1010.11
ProcVersionSignature: Ubuntu 4.15.0-1010.11-raspi2 4.15.17
Uname: Linux 4.15.0-1010-raspi2 armv7l
ApportVersion: 2.20.9-0ubuntu7
Architecture: armhf
Date: Tue May 1 23:24:58 2018
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-raspi2
UpgradeStatus: Upgraded to bionic on 2018-04-21 (10 days ago)

[Ryan Finnie (fo0bar)]

(ProcCpuinfoMinimal.txt indicates a Pi 3, not 3 B+, but that's the hardware the userland was attached to while reporting this. The dmesg output is from when it was attached to a 3 B+).