4.18-stable review patch. If anyone has any objections, please let me know.
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From: Russell King rmk+kernel@armlinux.org.uk
[ Upstream commit 126d6848ef13958e1cb959e96c21d19bc498ade9 ]
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.fainelli@gmail.com Tested-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: Russell King rmk+kernel@armlinux.org.uk Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/phy/sfp-bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/net/phy/sfp-bus.c +++ b/drivers/net/phy/sfp-bus.c @@ -349,6 +349,7 @@ static int sfp_register_bus(struct sfp_b } if (bus->started) bus->socket_ops->start(bus->sfp); + bus->netdev->sfp_bus = bus; bus->registered = true; return 0; } @@ -357,6 +358,7 @@ static void sfp_unregister_bus(struct sf { const struct sfp_upstream_ops *ops = bus->upstream_ops;
+ bus->netdev->sfp_bus = NULL; if (bus->registered) { if (bus->started) bus->socket_ops->stop(bus->sfp); @@ -438,7 +440,6 @@ static void sfp_upstream_clear(struct sf { bus->upstream_ops = NULL; bus->upstream = NULL; - bus->netdev->sfp_bus = NULL; bus->netdev = NULL; }
@@ -467,7 +468,6 @@ struct sfp_bus *sfp_register_upstream(st bus->upstream_ops = ops; bus->upstream = upstream; bus->netdev = ndev; - ndev->sfp_bus = bus;
if (bus->sfp) { ret = sfp_register_bus(bus);