From b37f78f234bf4fd98979d6c3ccc0f85e508f978f Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Fri, 16 Feb 2018 15:56:37 -0700 Subject: [PATCH 1/3] net: qualcomm: rmnet: Fix crash on real dev unregistration With CONFIG_DEBUG_PREEMPT enabled, a crash with the following call stack was observed when removing a real dev which had rmnet devices attached to it. To fix this, remove the netdev_upper link APIs and instead use the existing information in rmnet_port and rmnet_priv to get the association between real and rmnet devs. BUG: sleeping function called from invalid context in_atomic(): 0, irqs_disabled(): 0, pid: 5762, name: ip Preemption disabled at: [] debug_object_active_state+0xa4/0x16c Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: PC is at ___might_sleep+0x13c/0x180 LR is at ___might_sleep+0x17c/0x180 [] ___might_sleep+0x13c/0x180 [] __might_sleep+0x58/0x8c [] mutex_lock+0x2c/0x48 [] kernfs_remove_by_name_ns+0x48/0xa8 [] sysfs_remove_link+0x30/0x58 [] __netdev_adjacent_dev_remove+0x14c/0x1e0 [] __netdev_adjacent_dev_unlink_lists+0x40/0x68 [] netdev_upper_dev_unlink+0xb4/0x1fc [] rmnet_dev_walk_unreg+0x6c/0xc8 [] netdev_walk_all_lower_dev_rcu+0x58/0xb4 [] rmnet_config_notify_cb+0xf4/0x134 [] raw_notifier_call_chain+0x58/0x78 [] call_netdevice_notifiers_info+0x48/0x78 [] rollback_registered_many+0x230/0x3c8 [] unregister_netdevice_many+0x38/0x94 [] rtnl_delete_link+0x58/0x88 [] rtnl_dellink+0xbc/0x1cc [] rtnetlink_rcv_msg+0xb0/0x244 [] netlink_rcv_skb+0xb4/0xdc [] rtnetlink_rcv+0x34/0x44 [] netlink_unicast+0x1ec/0x294 [] netlink_sendmsg+0x320/0x390 [] sock_sendmsg+0x54/0x60 [] ___sys_sendmsg+0x298/0x2b0 [] SyS_sendmsg+0xb4/0xf0 [] el0_svc_naked+0x24/0x28 Fixes: ceed73a2cf4a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Fixes: 60d58f971c10 ("net: qualcomm: rmnet: Implement bridge mode") Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller --- .../ethernet/qualcomm/rmnet/rmnet_config.c | 68 ++++--------------- 1 file changed, 14 insertions(+), 54 deletions(-) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c index 7e7704daf5f1..c4949183eef3 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c @@ -43,12 +43,6 @@ /* Local Definitions and Declarations */ -struct rmnet_walk_data { - struct net_device *real_dev; - struct list_head *head; - struct rmnet_port *port; -}; - static int rmnet_is_real_dev_registered(const struct net_device *real_dev) { return rcu_access_pointer(real_dev->rx_handler) == rmnet_rx_handler; @@ -112,17 +106,14 @@ static int rmnet_register_real_device(struct net_device *real_dev) static void rmnet_unregister_bridge(struct net_device *dev, struct rmnet_port *port) { - struct net_device *rmnet_dev, *bridge_dev; struct rmnet_port *bridge_port; + struct net_device *bridge_dev; if (port->rmnet_mode != RMNET_EPMODE_BRIDGE) return; /* bridge slave handling */ if (!port->nr_rmnet_devs) { - rmnet_dev = netdev_master_upper_dev_get_rcu(dev); - netdev_upper_dev_unlink(dev, rmnet_dev); - bridge_dev = port->bridge_ep; bridge_port = rmnet_get_port_rtnl(bridge_dev); @@ -132,9 +123,6 @@ static void rmnet_unregister_bridge(struct net_device *dev, bridge_dev = port->bridge_ep; bridge_port = rmnet_get_port_rtnl(bridge_dev); - rmnet_dev = netdev_master_upper_dev_get_rcu(bridge_dev); - netdev_upper_dev_unlink(bridge_dev, rmnet_dev); - rmnet_unregister_real_device(bridge_dev, bridge_port); } } @@ -173,10 +161,6 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev, if (err) goto err1; - err = netdev_master_upper_dev_link(dev, real_dev, NULL, NULL, extack); - if (err) - goto err2; - port->rmnet_mode = mode; hlist_add_head_rcu(&ep->hlnode, &port->muxed_ep[mux_id]); @@ -193,8 +177,6 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev, return 0; -err2: - rmnet_vnd_dellink(mux_id, port, ep); err1: rmnet_unregister_real_device(real_dev, port); err0: @@ -204,14 +186,13 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev, static void rmnet_dellink(struct net_device *dev, struct list_head *head) { + struct rmnet_priv *priv = netdev_priv(dev); struct net_device *real_dev; struct rmnet_endpoint *ep; struct rmnet_port *port; u8 mux_id; - rcu_read_lock(); - real_dev = netdev_master_upper_dev_get_rcu(dev); - rcu_read_unlock(); + real_dev = priv->real_dev; if (!real_dev || !rmnet_is_real_dev_registered(real_dev)) return; @@ -219,7 +200,6 @@ static void rmnet_dellink(struct net_device *dev, struct list_head *head) port = rmnet_get_port_rtnl(real_dev); mux_id = rmnet_vnd_get_mux(dev); - netdev_upper_dev_unlink(dev, real_dev); ep = rmnet_get_endpoint(port, mux_id); if (ep) { @@ -233,30 +213,13 @@ static void rmnet_dellink(struct net_device *dev, struct list_head *head) unregister_netdevice_queue(dev, head); } -static int rmnet_dev_walk_unreg(struct net_device *rmnet_dev, void *data) -{ - struct rmnet_walk_data *d = data; - struct rmnet_endpoint *ep; - u8 mux_id; - - mux_id = rmnet_vnd_get_mux(rmnet_dev); - ep = rmnet_get_endpoint(d->port, mux_id); - if (ep) { - hlist_del_init_rcu(&ep->hlnode); - rmnet_vnd_dellink(mux_id, d->port, ep); - kfree(ep); - } - netdev_upper_dev_unlink(rmnet_dev, d->real_dev); - unregister_netdevice_queue(rmnet_dev, d->head); - - return 0; -} - static void rmnet_force_unassociate_device(struct net_device *dev) { struct net_device *real_dev = dev; - struct rmnet_walk_data d; + struct hlist_node *tmp_ep; + struct rmnet_endpoint *ep; struct rmnet_port *port; + unsigned long bkt_ep; LIST_HEAD(list); if (!rmnet_is_real_dev_registered(real_dev)) @@ -264,16 +227,19 @@ static void rmnet_force_unassociate_device(struct net_device *dev) ASSERT_RTNL(); - d.real_dev = real_dev; - d.head = &list; - port = rmnet_get_port_rtnl(dev); - d.port = port; rcu_read_lock(); rmnet_unregister_bridge(dev, port); - netdev_walk_all_lower_dev_rcu(real_dev, rmnet_dev_walk_unreg, &d); + hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) { + unregister_netdevice_queue(ep->egress_dev, &list); + rmnet_vnd_dellink(ep->mux_id, port, ep); + + hlist_del_init_rcu(&ep->hlnode); + kfree(ep); + } + rcu_read_unlock(); unregister_netdevice_many(&list); @@ -422,11 +388,6 @@ int rmnet_add_bridge(struct net_device *rmnet_dev, if (err) return -EBUSY; - err = netdev_master_upper_dev_link(slave_dev, rmnet_dev, NULL, NULL, - extack); - if (err) - return -EINVAL; - slave_port = rmnet_get_port(slave_dev); slave_port->rmnet_mode = RMNET_EPMODE_BRIDGE; slave_port->bridge_ep = real_dev; @@ -449,7 +410,6 @@ int rmnet_del_bridge(struct net_device *rmnet_dev, port->rmnet_mode = RMNET_EPMODE_VND; port->bridge_ep = NULL; - netdev_upper_dev_unlink(slave_dev, rmnet_dev); slave_port = rmnet_get_port(slave_dev); rmnet_unregister_real_device(slave_dev, slave_port); From 4dba8bbce94541c560940ac65ca9cd563fd43348 Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Fri, 16 Feb 2018 15:56:38 -0700 Subject: [PATCH 2/3] net: qualcomm: rmnet: Fix warning seen with 64 bit stats With CONFIG_DEBUG_PREEMPT enabled, a warning was seen on device creation. This occurs due to the incorrect cpu API usage in ndo_get_stats64 handler. BUG: using smp_processor_id() in preemptible [00000000] code: rmnetcli/5743 caller is debug_smp_processor_id+0x1c/0x24 Call trace: [] dump_backtrace+0x0/0x2a8 [] show_stack+0x20/0x28 [] dump_stack+0xa8/0xe0 [] check_preemption_disabled+0x104/0x108 [] debug_smp_processor_id+0x1c/0x24 [] rmnet_get_stats64+0x64/0x13c [] dev_get_stats+0x68/0xd8 [] rtnl_fill_stats+0x54/0x140 [] rtnl_fill_ifinfo+0x428/0x9cc [] rtmsg_ifinfo_build_skb+0x80/0xf4 [] rtnetlink_event+0x88/0xb4 [] raw_notifier_call_chain+0x58/0x78 [] call_netdevice_notifiers_info+0x48/0x78 [] __netdev_upper_dev_link+0x290/0x5e8 [] netdev_master_upper_dev_link+0x3c/0x48 [] rmnet_newlink+0xf0/0x1c8 [] rtnl_newlink+0x57c/0x6c8 [] rtnetlink_rcv_msg+0xb0/0x244 [] netlink_rcv_skb+0xb4/0xdc [] rtnetlink_rcv+0x34/0x44 [] netlink_unicast+0x1ec/0x294 [] netlink_sendmsg+0x320/0x390 [] sock_sendmsg+0x54/0x60 [] SyS_sendto+0x1a0/0x1e4 [] el0_svc_naked+0x24/0x28 Fixes: 192c4b5d48f2 ("net: qualcomm: rmnet: Add support for 64 bit stats") Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller --- drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c index 570a227acdd8..346d310914df 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c @@ -121,7 +121,7 @@ static void rmnet_get_stats64(struct net_device *dev, memset(&total_stats, 0, sizeof(struct rmnet_vnd_stats)); for_each_possible_cpu(cpu) { - pcpu_ptr = this_cpu_ptr(priv->pcpu_stats); + pcpu_ptr = per_cpu_ptr(priv->pcpu_stats, cpu); do { start = u64_stats_fetch_begin_irq(&pcpu_ptr->syncp); From f57bbaae7271a47dc6486d489c503faeb248b6d5 Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Fri, 16 Feb 2018 15:56:39 -0700 Subject: [PATCH 3/3] net: qualcomm: rmnet: Fix possible null dereference in command processing If a command packet with invalid mux id is received, the packet would not have a valid endpoint. This invalid endpoint maybe dereferenced leading to a crash. Identified by manual code inspection. Fixes: 3352e6c45760 ("net: qualcomm: rmnet: Convert the muxed endpoint to hlist") Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller --- drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c index 6bc328fb88e1..b0dbca070c00 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c @@ -38,6 +38,11 @@ static u8 rmnet_map_do_flow_control(struct sk_buff *skb, } ep = rmnet_get_endpoint(port, mux_id); + if (!ep) { + kfree_skb(skb); + return RX_HANDLER_CONSUMED; + } + vnd = ep->egress_dev; ip_family = cmd->flow_control.ip_family;