From d09486a04f5da0a812c26217213b89a3b1acf836 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 18 Jan 2024 16:58:59 -0800 Subject: net: fix removing a namespace with conflicting altnames MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Mark reports a BUG() when a net namespace is removed. kernel BUG at net/core/dev.c:11520! Physical interfaces moved outside of init_net get "refunded" to init_net when that namespace disappears. The main interface name may get overwritten in the process if it would have conflicted. We need to also discard all conflicting altnames. Recent fixes addressed ensuring that altnames get moved with the main interface, which surfaced this problem. Reported-by: Марк Коренберг Link: https://lore.kernel.org/all/CAEmTpZFZ4Sv3KwqFOY2WKDHeZYdi0O7N5H1nTvcGp=SAEavtDg@mail.gmail.com/ Fixes: 7663d522099e ("net: check for altname conflicts when changing netdev's netns") Signed-off-by: Jakub Kicinski Reviewed-by: Eric Dumazet Reviewed-by: Jiri Pirko Reviewed-by: Xin Long Signed-off-by: David S. Miller --- net/core/dev.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index f01a9b858347..cb2dab0feee0 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11551,6 +11551,7 @@ static struct pernet_operations __net_initdata netdev_net_ops = { static void __net_exit default_device_exit_net(struct net *net) { + struct netdev_name_node *name_node, *tmp; struct net_device *dev, *aux; /* * Push all migratable network devices back to the @@ -11573,6 +11574,14 @@ static void __net_exit default_device_exit_net(struct net *net) snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex); if (netdev_name_in_use(&init_net, fb_name)) snprintf(fb_name, IFNAMSIZ, "dev%%d"); + + netdev_for_each_altname_safe(dev, name_node, tmp) + if (netdev_name_in_use(&init_net, name_node->name)) { + netdev_name_node_del(name_node); + synchronize_rcu(); + __netdev_name_node_alt_destroy(name_node); + } + err = dev_change_net_namespace(dev, &init_net, fb_name); if (err) { pr_emerg("%s: failed to move %s to init_net: %d\n", -- cgit v1.2.3 From c353c7b7ffb7ae6ed8f3339906fe33c8be6cf344 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 8 Feb 2024 14:43:23 +0000 Subject: net-device: move lstats in net_device_read_txrx dev->lstats is notably used from loopback ndo_start_xmit() and other virtual drivers. Per cpu stats updates are dirtying per-cpu data, but the pointer itself is read-only. Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables") Signed-off-by: Eric Dumazet Cc: Coco Li Cc: Simon Horman Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- Documentation/networking/net_cachelines/net_device.rst | 4 ++-- include/linux/netdevice.h | 10 +++++----- net/core/dev.c | 3 ++- 3 files changed, 9 insertions(+), 8 deletions(-) (limited to 'net/core/dev.c') diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Documentation/networking/net_cachelines/net_device.rst index e75a53593bb9..dceb49d56a91 100644 --- a/Documentation/networking/net_cachelines/net_device.rst +++ b/Documentation/networking/net_cachelines/net_device.rst @@ -136,8 +136,8 @@ struct_netpoll_info* npinfo - possible_net_t nd_net - read_mostly (dev_net)napi_busy_loop,tcp_v(4/6)_rcv,ip(v6)_rcv,ip(6)_input,ip(6)_input_finish void* ml_priv enum_netdev_ml_priv_type ml_priv_type -struct_pcpu_lstats__percpu* lstats -struct_pcpu_sw_netstats__percpu* tstats +struct_pcpu_lstats__percpu* lstats read_mostly dev_lstats_add() +struct_pcpu_sw_netstats__percpu* tstats read_mostly dev_sw_netstats_tx_add() struct_pcpu_dstats__percpu* dstats struct_garp_port* garp_port struct_mrp_port* mrp_port diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 118c40258d07..ef7bfbb98497 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2141,6 +2141,11 @@ struct net_device { /* TXRX read-mostly hotpath */ __cacheline_group_begin(net_device_read_txrx); + union { + struct pcpu_lstats __percpu *lstats; + struct pcpu_sw_netstats __percpu *tstats; + struct pcpu_dstats __percpu *dstats; + }; unsigned int flags; unsigned short hard_header_len; netdev_features_t features; @@ -2395,11 +2400,6 @@ struct net_device { enum netdev_ml_priv_type ml_priv_type; enum netdev_stat_type pcpu_stat_type:8; - union { - struct pcpu_lstats __percpu *lstats; - struct pcpu_sw_netstats __percpu *tstats; - struct pcpu_dstats __percpu *dstats; - }; #if IS_ENABLED(CONFIG_GARP) struct garp_port __rcu *garp_port; diff --git a/net/core/dev.c b/net/core/dev.c index cb2dab0feee0..9bb792cecc16 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11652,11 +11652,12 @@ static void __init net_dev_struct_check(void) CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_tx, 160); /* TXRX read-mostly hotpath */ + CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, lstats); CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, flags); CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, hard_header_len); CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, features); CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_txrx, ip6_ptr); - CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_txrx, 30); + CACHELINE_ASSERT_GROUP_SIZE(struct net_device, net_device_read_txrx, 38); /* RX read-mostly hotpath */ CACHELINE_ASSERT_GROUP_MEMBER(struct net_device, net_device_read_rx, ptype_specific); -- cgit v1.2.3 From 9f30831390ede02d9fcd54fd9ea5a585ab649f4a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 9 Feb 2024 18:12:48 +0000 Subject: net: add rcu safety to rtnl_prop_list_size() rtnl_prop_list_size() can be called while alternative names are added or removed concurrently. if_nlmsg_size() / rtnl_calcit() can indeed be called without RTNL held. Use explicit RCU protection to avoid UAF. Fixes: 88f4fb0c7496 ("net: rtnetlink: put alternative names to getlink message") Signed-off-by: Eric Dumazet Cc: Jiri Pirko Link: https://lore.kernel.org/r/20240209181248.96637-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/core/dev.c | 2 +- net/core/rtnetlink.c | 15 +++++++++------ 2 files changed, 10 insertions(+), 7 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 9bb792cecc16..73a021973007 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -336,7 +336,7 @@ int netdev_name_node_alt_create(struct net_device *dev, const char *name) return -ENOMEM; netdev_name_node_add(net, name_node); /* The node that holds dev->name acts as a head of per-device list. */ - list_add_tail(&name_node->list, &dev->name_node->list); + list_add_tail_rcu(&name_node->list, &dev->name_node->list); return 0; } diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index f6f29eb03ec2..9c4f427f3a50 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1020,14 +1020,17 @@ static size_t rtnl_xdp_size(void) static size_t rtnl_prop_list_size(const struct net_device *dev) { struct netdev_name_node *name_node; - size_t size; + unsigned int cnt = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(name_node, &dev->name_node->list, list) + cnt++; + rcu_read_unlock(); - if (list_empty(&dev->name_node->list)) + if (!cnt) return 0; - size = nla_total_size(0); - list_for_each_entry(name_node, &dev->name_node->list, list) - size += nla_total_size(ALTIFNAMSIZ); - return size; + + return nla_total_size(0) + cnt * nla_total_size(ALTIFNAMSIZ); } static size_t rtnl_proto_down_size(const struct net_device *dev) -- cgit v1.2.3