From 64e86fec54069266ba32be551d7b7f75e88ab60c Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Tue, 17 Apr 2018 17:40:00 -0600 Subject: [PATCH] net: qualcomm: rmnet: Fix warning seen with fill_info When the last rmnet device attached to a real device is removed, the real device is unregistered from rmnet. As a result, the real device lookup fails resulting in a warning when the fill_info handler is called as part of the rmnet device unregistration. Fix this by returning the rmnet flags as 0 when no real device is present. WARNING: CPU: 0 PID: 1779 at net/core/rtnetlink.c:3254 rtmsg_ifinfo_build_skb+0xca/0x10d Modules linked in: CPU: 0 PID: 1779 Comm: ip Not tainted 4.16.0-11872-g7ce2367 #1 Stack: 7fe655f0 60371ea3 00000000 00000000 60282bc6 6006b116 7fe65600 60371ee8 7fe65660 6003a68c 00000000 900000000 Call Trace: [<6006b116>] ? printk+0x0/0x94 [<6001f375>] show_stack+0xfe/0x158 [<60371ea3>] ? dump_stack_print_info+0xe8/0xf1 [<60282bc6>] ? rtmsg_ifinfo_build_skb+0xca/0x10d [<6006b116>] ? printk+0x0/0x94 [<60371ee8>] dump_stack+0x2a/0x2c [<6003a68c>] __warn+0x10e/0x13e [<6003a82c>] warn_slowpath_null+0x48/0x4f [<60282bc6>] rtmsg_ifinfo_build_skb+0xca/0x10d [<60282c4d>] rtmsg_ifinfo_event.part.37+0x1e/0x43 [<60282c2f>] ? rtmsg_ifinfo_event.part.37+0x0/0x43 [<60282d03>] rtmsg_ifinfo+0x24/0x28 [<60264e86>] dev_close_many+0xba/0x119 [<60282cdf>] ? rtmsg_ifinfo+0x0/0x28 [<6027c225>] ? rtnl_is_locked+0x0/0x1c [<6026ca67>] rollback_registered_many+0x1ae/0x4ae [<600314be>] ? unblock_signals+0x0/0xae [<6026cdc0>] ? unregister_netdevice_queue+0x19/0xec [<6026ceec>] unregister_netdevice_many+0x21/0xa1 [<6027c765>] rtnl_delete_link+0x3e/0x4e [<60280ecb>] rtnl_dellink+0x262/0x29c [<6027c241>] ? rtnl_get_link+0x0/0x3e [<6027f867>] rtnetlink_rcv_msg+0x235/0x274 Fixes: be81a85f5f87 ("net: qualcomm: rmnet: Implement fill_info") Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller --- drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c index d33988570217..5f4e447c5dce 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c @@ -350,15 +350,16 @@ static int rmnet_fill_info(struct sk_buff *skb, const struct net_device *dev) real_dev = priv->real_dev; - if (!rmnet_is_real_dev_registered(real_dev)) - return -ENODEV; - if (nla_put_u16(skb, IFLA_RMNET_MUX_ID, priv->mux_id)) goto nla_put_failure; - port = rmnet_get_port_rtnl(real_dev); + if (rmnet_is_real_dev_registered(real_dev)) { + port = rmnet_get_port_rtnl(real_dev); + f.flags = port->data_format; + } else { + f.flags = 0; + } - f.flags = port->data_format; f.mask = ~0; if (nla_put(skb, IFLA_RMNET_FLAGS, sizeof(f), &f)) -- 2.30.2