4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> [ Upstream commit 0b2122e4934c7783d336397864e34ee53aad0965 ] When we remove a socket or upstream, and the other side isn't registered, we dereference a NULL pointer, causing a kernel oops. Fix this. Fixes: ce0aa27ff3f6 ("sfp: add sfp-bus to bridge between network devices and sfp cages") Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/phy/sfp-bus.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/net/phy/sfp-bus.c +++ b/drivers/net/phy/sfp-bus.c @@ -359,7 +359,8 @@ EXPORT_SYMBOL_GPL(sfp_register_upstream) void sfp_unregister_upstream(struct sfp_bus *bus) { rtnl_lock(); - sfp_unregister_bus(bus); + if (bus->sfp) + sfp_unregister_bus(bus); bus->upstream = NULL; bus->netdev = NULL; rtnl_unlock(); @@ -464,7 +465,8 @@ EXPORT_SYMBOL_GPL(sfp_register_socket); void sfp_unregister_socket(struct sfp_bus *bus) { rtnl_lock(); - sfp_unregister_bus(bus); + if (bus->netdev) + sfp_unregister_bus(bus); bus->sfp_dev = NULL; bus->sfp = NULL; bus->socket_ops = NULL;