From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:56574 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727579AbeJHWiN (ORCPT ); Mon, 8 Oct 2018 18:38:13 -0400 From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Russell King , "David S . Miller" , Sasha Levin Subject: [PATCH AUTOSEL 4.18 33/58] sfp: fix oops with ethtool -m Date: Mon, 8 Oct 2018 11:24:58 -0400 Message-Id: <20181008152523.70705-33-sashal@kernel.org> In-Reply-To: <20181008152523.70705-1-sashal@kernel.org> References: <20181008152523.70705-1-sashal@kernel.org> Sender: stable-owner@vger.kernel.org List-ID: From: Russell King [ 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 Tested-by: Florian Fainelli Signed-off-by: Russell King Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/phy/sfp-bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c index 740655261e5b..83060fb349f4 100644 --- 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_bus *bus) } 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 sfp_bus *bus) { 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 sfp_bus *bus) { 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(struct fwnode_handle *fwnode, bus->upstream_ops = ops; bus->upstream = upstream; bus->netdev = ndev; - ndev->sfp_bus = bus; if (bus->sfp) { ret = sfp_register_bus(bus); -- 2.17.1