From: Russell King <rmk+ker...@armlinux.org.uk>
Date: Tue, 18 Sep 2018 16:48:53 +0100
> If a network interface is created prior to the SFP socket being
> available, ethtool can request module information. This unfortunately
> leads to an oops:
>
> Unable to handle kernel NULL pointer dereference at virtual address 00000008
> pgd = (ptrval)
> [00000008] *pgd=7c400831, *pte=00000000, *ppte=00000000
> Internal error: Oops: 17 [#1] SMP ARM
> Modules linked in:
> CPU: 0 PID: 1480 Comm: ethtool Not tainted 4.19.0-rc3 #138
> Hardware name: Broadcom Northstar Plus SoC
> PC is at sfp_get_module_info+0x8/0x10
> LR is at dev_ethtool+0x218c/0x2afc
>
> Fix this by not filling in the network device's SFP bus pointer until
> SFP is fully bound, thereby avoiding the core calling into the SFP bus
> code.
>
> Fixes: ce0aa27ff3f6 ("sfp: add sfp-bus to bridge between network devices and
> sfp cages")
> Reported-by: Florian Fainelli <f.faine...@gmail.com>
> Tested-by: Florian Fainelli <f.faine...@gmail.com>
> Signed-off-by: Russell King <rmk+ker...@armlinux.org.uk>
Applied and queued up for -stable.
