linux/drivers/net/usb
Alexander Graf 92571a1aae lan78xx: Connect phy early
When using wicked with a lan78xx device attached to the system, we
end up with ethtool commands issued on the device before an ifup
got issued. That lead to the following crash:

    Unable to handle kernel NULL pointer dereference at virtual address 0000039c
    pgd = ffff800035b30000
    [0000039c] *pgd=0000000000000000
    Internal error: Oops: 96000004 [#1] SMP
    Modules linked in: [...]
    Supported: Yes
    CPU: 3 PID: 638 Comm: wickedd Tainted: G            E      4.12.14-0-default #1
    Hardware name: raspberrypi rpi/rpi, BIOS 2018.03-rc2 02/21/2018
    task: ffff800035e74180 task.stack: ffff800036718000
    PC is at phy_ethtool_ksettings_get+0x20/0x98
    LR is at lan78xx_get_link_ksettings+0x44/0x60 [lan78xx]
    pc : [<ffff0000086f7f30>] lr : [<ffff000000dcca84>] pstate: 20000005
    sp : ffff80003671bb20
    x29: ffff80003671bb20 x28: ffff800035e74180
    x27: ffff000008912000 x26: 000000000000001d
    x25: 0000000000000124 x24: ffff000008f74d00
    x23: 0000004000114809 x22: 0000000000000000
    x21: ffff80003671bbd0 x20: 0000000000000000
    x19: ffff80003671bbd0 x18: 000000000000040d
    x17: 0000000000000001 x16: 0000000000000000
    x15: 0000000000000000 x14: ffffffffffffffff
    x13: 0000000000000000 x12: 0000000000000020
    x11: 0101010101010101 x10: fefefefefefefeff
    x9 : 7f7f7f7f7f7f7f7f x8 : fefefeff31677364
    x7 : 0000000080808080 x6 : ffff80003671bc9c
    x5 : ffff80003671b9f8 x4 : ffff80002c296190
    x3 : 0000000000000000 x2 : 0000000000000000
    x1 : ffff80003671bbd0 x0 : ffff80003671bc00
    Process wickedd (pid: 638, stack limit = 0xffff800036718000)
    Call trace:
    Exception stack(0xffff80003671b9e0 to 0xffff80003671bb20)
    b9e0: ffff80003671bc00 ffff80003671bbd0 0000000000000000 0000000000000000
    ba00: ffff80002c296190 ffff80003671b9f8 ffff80003671bc9c 0000000080808080
    ba20: fefefeff31677364 7f7f7f7f7f7f7f7f fefefefefefefeff 0101010101010101
    ba40: 0000000000000020 0000000000000000 ffffffffffffffff 0000000000000000
    ba60: 0000000000000000 0000000000000001 000000000000040d ffff80003671bbd0
    ba80: 0000000000000000 ffff80003671bbd0 0000000000000000 0000004000114809
    baa0: ffff000008f74d00 0000000000000124 000000000000001d ffff000008912000
    bac0: ffff800035e74180 ffff80003671bb20 ffff000000dcca84 ffff80003671bb20
    bae0: ffff0000086f7f30 0000000020000005 ffff80002c296000 ffff800035223900
    bb00: 0000ffffffffffff 0000000000000000 ffff80003671bb20 ffff0000086f7f30
    [<ffff0000086f7f30>] phy_ethtool_ksettings_get+0x20/0x98
    [<ffff000000dcca84>] lan78xx_get_link_ksettings+0x44/0x60 [lan78xx]
    [<ffff0000087cbc40>] ethtool_get_settings+0x68/0x210
    [<ffff0000087cc0d4>] dev_ethtool+0x214/0x2180
    [<ffff0000087e5008>] dev_ioctl+0x400/0x630
    [<ffff00000879dd00>] sock_do_ioctl+0x70/0x88
    [<ffff00000879f5f8>] sock_ioctl+0x208/0x368
    [<ffff0000082cde10>] do_vfs_ioctl+0xb0/0x848
    [<ffff0000082ce634>] SyS_ioctl+0x8c/0xa8
    Exception stack(0xffff80003671bec0 to 0xffff80003671c000)
    bec0: 0000000000000009 0000000000008946 0000fffff4e841d0 0000aa0032687465
    bee0: 0000aaaafa2319d4 0000fffff4e841d4 0000000032687465 0000000032687465
    bf00: 000000000000001d 7f7fff7f7f7f7f7f 72606b622e71ff4c 7f7f7f7f7f7f7f7f
    bf20: 0101010101010101 0000000000000020 ffffffffffffffff 0000ffff7f510c68
    bf40: 0000ffff7f6a9d18 0000ffff7f44ce30 000000000000040d 0000ffff7f6f98f0
    bf60: 0000fffff4e842c0 0000000000000001 0000aaaafa2c2e00 0000ffff7f6ab000
    bf80: 0000fffff4e842c0 0000ffff7f62a000 0000aaaafa2b9f20 0000aaaafa2c2e00
    bfa0: 0000fffff4e84818 0000fffff4e841a0 0000ffff7f5ad0cc 0000fffff4e841a0
    bfc0: 0000ffff7f44ce3c 0000000080000000 0000000000000009 000000000000001d
    bfe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000

The culprit is quite simple: The driver tries to access the phy left and right,
but only actually has a working reference to it when the device is up.

The fix thus is quite simple too: Get a reference to the phy on probe already
and keep it even when the device is going down.

With this patch applied, I can successfully run wicked on my system and bring
the interface up and down as many times as I want, without getting NULL pointer
dereferences in between.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04 11:41:03 -04:00
..
Kconfig usb: plusb: Add support for PL-27A1 2017-04-25 10:08:16 -04:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
asix.h asix: Fix small memory leak in ax88772_unbind() 2017-08-07 10:10:19 -07:00
asix_common.c net: Remove useless function skb_header_release 2017-09-22 20:43:13 -07:00
asix_devices.c net: usb: asix: fill null-ptr-deref in asix_suspend 2017-11-09 09:22:13 +09:00
ax88172a.c net: usbnet: support 64bit stats 2017-04-03 19:09:40 -07:00
ax88179_178a.c Revert "net: usb: asix88179_178a: de-duplicate code" 2018-04-01 14:04:58 -04:00
catc.c net: usb: Convert timers to use timer_setup() 2017-10-18 12:40:26 +01:00
cdc-phonet.c net: usb: cdc-phonet: constify usb_device_id 2017-08-08 17:47:58 -07:00
cdc_eem.c net: cdc_eem: clean up bind error path 2018-03-07 15:39:27 -05:00
cdc_ether.c cdc_ether: flag the Cinterion PLS8 modem by gemalto as WWAN 2018-02-27 14:44:36 -05:00
cdc_mbim.c net: cdc_mbim: apply "NDP to end" quirk to HP lt4132 2017-07-03 02:19:36 -07:00
cdc_ncm.c drivers/net: Use octal not symbolic permissions 2018-03-26 12:07:49 -04:00
cdc_subset.c
ch9200.c net: ch9200: add missing USB-descriptor endianness conversions 2017-05-12 12:15:46 -04:00
cx82310_eth.c cx82310_eth: use skb_cow_head() to deal with cloned skbs 2017-04-21 13:24:05 -04:00
dm9601.c net: usbnet: support 64bit stats 2017-04-03 19:09:40 -07:00
gl620a.c networking: make skb_push & __skb_push return void pointers 2017-06-16 11:48:40 -04:00
hso.c drivers/net: Use octal not symbolic permissions 2018-03-26 12:07:49 -04:00
huawei_cdc_ncm.c cdc_ncm: Set NTB format again after altsetting switch for Huawei devices 2017-07-14 08:15:05 -07:00
int51x1.c net: introduce __skb_put_[zero, data, u8] 2017-06-20 13:30:14 -04:00
ipheth.c usbnet: ipheth: fix potential null pointer dereference in ipheth_carrier_set 2017-11-19 12:23:57 +09:00
kalmia.c net: kalmia: clean up bind error path 2018-03-07 15:39:27 -05:00
kaweth.c net: usb: kaweth: constify usb_device_id 2017-08-08 17:47:59 -07:00
lan78xx.c lan78xx: Connect phy early 2018-04-04 11:41:03 -04:00
lan78xx.h lan78xx: add LAN7801 MAC only support 2016-12-08 14:21:47 -05:00
lg-vl600.c net: drivers/net: Remove unnecessary skb_copy_expand OOM messages 2018-03-15 14:28:03 -04:00
mcs7830.c net: usbnet: support 64bit stats 2017-04-03 19:09:40 -07:00
net1080.c networking: add and use skb_put_u8() 2017-06-16 11:48:40 -04:00
pegasus.c usbnet: pegasus: Use net_device_stats from struct net_device 2017-04-07 07:03:33 -07:00
pegasus.h usbnet: pegasus: Use net_device_stats from struct net_device 2017-04-07 07:03:33 -07:00
plusb.c usb: plusb: Add support for PL-27A1 2017-04-25 10:08:16 -04:00
qmi_wwan.c net-usb: add qmi_wwan if on lte modem wistron neweb d18q1 2018-03-27 10:51:10 -04:00
r8152.c r8152: fix tx packets accounting 2018-02-26 21:01:53 -05:00
rndis_host.c rndis_host: support Novatel Verizon USB730L 2017-10-03 14:30:46 -07:00
rtl8150.c net: usb: rtl8150: constify usb_device_id 2017-08-08 17:47:59 -07:00
sierra_net.c net: usb: Convert timers to use timer_setup() 2017-10-18 12:40:26 +01:00
smsc75xx.c smsc75xx: fix smsc75xx_set_features() 2018-02-22 14:05:15 -05:00
smsc75xx.h
smsc95xx.c smsc95xx: Configure pause time to 0xffff when tx flow control enabled 2017-09-12 20:36:30 -07:00
smsc95xx.h smsc95xx: Add comments to the registers definition 2017-04-17 13:04:52 -04:00
sr9700.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-21 20:23:53 -07:00
sr9700.h
sr9800.c net: usbnet: support 64bit stats 2017-04-03 19:09:40 -07:00
sr9800.h
usbnet.c net: usbnet: fix potential deadlock on 32bit hosts 2018-03-07 11:46:39 -05:00
zaurus.c networking: add and use skb_put_u8() 2017-06-16 11:48:40 -04:00