From 20e61da7ffcfd84a1b6f797e745608572e5bc218 Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Fri, 25 Jul 2014 15:25:08 -0700 Subject: [PATCH 1/3] ipv4: fail early when creating netdev named all or default We create a proc dir for each network device, this will cause conflicts when the devices have name "all" or "default". Rather than emitting an ugly kernel warning, we could just fail earlier by checking the device name. Reported-by: Stephane Chazelas Cc: "David S. Miller" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- include/net/ip.h | 6 ++++++ net/ipv4/devinet.c | 36 +++++++++++++++++++++++++++--------- 2 files changed, 33 insertions(+), 9 deletions(-) diff --git a/include/net/ip.h b/include/net/ip.h index ca14799545fd..09b32da1b929 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -216,6 +216,12 @@ static inline int inet_is_local_reserved_port(struct net *net, int port) return 0; return test_bit(port, net->ipv4.sysctl_local_reserved_ports); } + +static inline bool sysctl_dev_name_is_allowed(const char *name) +{ + return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; +} + #else static inline int inet_is_local_reserved_port(struct net *net, int port) { diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index e9449376b58e..214882e7d6de 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -180,11 +180,12 @@ static BLOCKING_NOTIFIER_HEAD(inetaddr_chain); static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap, int destroy); #ifdef CONFIG_SYSCTL -static void devinet_sysctl_register(struct in_device *idev); +static int devinet_sysctl_register(struct in_device *idev); static void devinet_sysctl_unregister(struct in_device *idev); #else -static void devinet_sysctl_register(struct in_device *idev) +static int devinet_sysctl_register(struct in_device *idev) { + return 0; } static void devinet_sysctl_unregister(struct in_device *idev) { @@ -232,6 +233,7 @@ EXPORT_SYMBOL(in_dev_finish_destroy); static struct in_device *inetdev_init(struct net_device *dev) { struct in_device *in_dev; + int err = -ENOMEM; ASSERT_RTNL(); @@ -252,7 +254,13 @@ static struct in_device *inetdev_init(struct net_device *dev) /* Account for reference dev->ip_ptr (below) */ in_dev_hold(in_dev); - devinet_sysctl_register(in_dev); + err = devinet_sysctl_register(in_dev); + if (err) { + in_dev->dead = 1; + in_dev_put(in_dev); + in_dev = NULL; + goto out; + } ip_mc_init_dev(in_dev); if (dev->flags & IFF_UP) ip_mc_up(in_dev); @@ -260,7 +268,7 @@ static struct in_device *inetdev_init(struct net_device *dev) /* we can receive as soon as ip_ptr is set -- do this last */ rcu_assign_pointer(dev->ip_ptr, in_dev); out: - return in_dev; + return in_dev ?: ERR_PTR(err); out_kfree: kfree(in_dev); in_dev = NULL; @@ -1347,8 +1355,8 @@ static int inetdev_event(struct notifier_block *this, unsigned long event, if (!in_dev) { if (event == NETDEV_REGISTER) { in_dev = inetdev_init(dev); - if (!in_dev) - return notifier_from_errno(-ENOMEM); + if (IS_ERR(in_dev)) + return notifier_from_errno(PTR_ERR(in_dev)); if (dev->flags & IFF_LOOPBACK) { IN_DEV_CONF_SET(in_dev, NOXFRM, 1); IN_DEV_CONF_SET(in_dev, NOPOLICY, 1); @@ -2182,11 +2190,21 @@ static void __devinet_sysctl_unregister(struct ipv4_devconf *cnf) kfree(t); } -static void devinet_sysctl_register(struct in_device *idev) +static int devinet_sysctl_register(struct in_device *idev) { - neigh_sysctl_register(idev->dev, idev->arp_parms, NULL); - __devinet_sysctl_register(dev_net(idev->dev), idev->dev->name, + int err; + + if (!sysctl_dev_name_is_allowed(idev->dev->name)) + return -EINVAL; + + err = neigh_sysctl_register(idev->dev, idev->arp_parms, NULL); + if (err) + return err; + err = __devinet_sysctl_register(dev_net(idev->dev), idev->dev->name, &idev->cnf); + if (err) + neigh_sysctl_unregister(idev->arp_parms); + return err; } static void devinet_sysctl_unregister(struct in_device *idev) From a317a2f19da7d0af1f068cf4d3ae80cdd73643b7 Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Fri, 25 Jul 2014 15:25:09 -0700 Subject: [PATCH 2/3] ipv6: fail early when creating netdev named all or default We create a proc dir for each network device, this will cause conflicts when the devices have name "all" or "default". Rather than emitting an ugly kernel warning, we could just fail earlier by checking the device name. Reported-by: Stephane Chazelas Cc: "David S. Miller" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 82 +++++++++++++++++++++++++++++---------------- 1 file changed, 54 insertions(+), 28 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 4c03c2843094..0b239fc1816e 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -108,11 +108,12 @@ static inline u32 cstamp_delta(unsigned long cstamp) } #ifdef CONFIG_SYSCTL -static void addrconf_sysctl_register(struct inet6_dev *idev); +static int addrconf_sysctl_register(struct inet6_dev *idev); static void addrconf_sysctl_unregister(struct inet6_dev *idev); #else -static inline void addrconf_sysctl_register(struct inet6_dev *idev) +static inline int addrconf_sysctl_register(struct inet6_dev *idev) { + return 0; } static inline void addrconf_sysctl_unregister(struct inet6_dev *idev) @@ -310,16 +311,16 @@ err_ip: static struct inet6_dev *ipv6_add_dev(struct net_device *dev) { struct inet6_dev *ndev; + int err = -ENOMEM; ASSERT_RTNL(); if (dev->mtu < IPV6_MIN_MTU) - return NULL; + return ERR_PTR(-EINVAL); ndev = kzalloc(sizeof(struct inet6_dev), GFP_KERNEL); - if (ndev == NULL) - return NULL; + return ERR_PTR(err); rwlock_init(&ndev->lock); ndev->dev = dev; @@ -332,7 +333,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) ndev->nd_parms = neigh_parms_alloc(dev, &nd_tbl); if (ndev->nd_parms == NULL) { kfree(ndev); - return NULL; + return ERR_PTR(err); } if (ndev->cnf.forwarding) dev_disable_lro(dev); @@ -346,17 +347,14 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) neigh_parms_release(&nd_tbl, ndev->nd_parms); dev_put(dev); kfree(ndev); - return NULL; + return ERR_PTR(err); } if (snmp6_register_dev(ndev) < 0) { ADBG(KERN_WARNING "%s: cannot create /proc/net/dev_snmp6/%s\n", __func__, dev->name); - neigh_parms_release(&nd_tbl, ndev->nd_parms); - ndev->dead = 1; - in6_dev_finish_destroy(ndev); - return NULL; + goto err_release; } /* One reference from device. We must do this before @@ -394,7 +392,12 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) ipv6_mc_init_dev(ndev); ndev->tstamp = jiffies; - addrconf_sysctl_register(ndev); + err = addrconf_sysctl_register(ndev); + if (err) { + ipv6_mc_destroy_dev(ndev); + del_timer(&ndev->regen_timer); + goto err_release; + } /* protected by rtnl_lock */ rcu_assign_pointer(dev->ip6_ptr, ndev); @@ -409,6 +412,12 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters); return ndev; + +err_release: + neigh_parms_release(&nd_tbl, ndev->nd_parms); + ndev->dead = 1; + in6_dev_finish_destroy(ndev); + return ERR_PTR(err); } static struct inet6_dev *ipv6_find_idev(struct net_device *dev) @@ -420,7 +429,7 @@ static struct inet6_dev *ipv6_find_idev(struct net_device *dev) idev = __in6_dev_get(dev); if (!idev) { idev = ipv6_add_dev(dev); - if (!idev) + if (IS_ERR(idev)) return NULL; } @@ -2830,8 +2839,8 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, case NETDEV_REGISTER: if (!idev && dev->mtu >= IPV6_MIN_MTU) { idev = ipv6_add_dev(dev); - if (!idev) - return notifier_from_errno(-ENOMEM); + if (IS_ERR(idev)) + return notifier_from_errno(PTR_ERR(idev)); } break; @@ -2851,7 +2860,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, if (!idev && dev->mtu >= IPV6_MIN_MTU) idev = ipv6_add_dev(dev); - if (idev) { + if (!IS_ERR_OR_NULL(idev)) { idev->if_flags |= IF_READY; run_pending = 1; } @@ -2894,7 +2903,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, break; } - if (idev) { + if (!IS_ERR_OR_NULL(idev)) { if (run_pending) addrconf_dad_run(idev); @@ -2929,7 +2938,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, if (!idev && dev->mtu >= IPV6_MIN_MTU) { idev = ipv6_add_dev(dev); - if (idev) + if (!IS_ERR(idev)) break; } @@ -2950,10 +2959,14 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, if (idev) { snmp6_unregister_dev(idev); addrconf_sysctl_unregister(idev); - addrconf_sysctl_register(idev); - err = snmp6_register_dev(idev); + err = addrconf_sysctl_register(idev); if (err) return notifier_from_errno(err); + err = snmp6_register_dev(idev); + if (err) { + addrconf_sysctl_unregister(idev); + return notifier_from_errno(err); + } } break; @@ -5248,12 +5261,23 @@ static void __addrconf_sysctl_unregister(struct ipv6_devconf *p) kfree(t); } -static void addrconf_sysctl_register(struct inet6_dev *idev) +static int addrconf_sysctl_register(struct inet6_dev *idev) { - neigh_sysctl_register(idev->dev, idev->nd_parms, - &ndisc_ifinfo_sysctl_change); - __addrconf_sysctl_register(dev_net(idev->dev), idev->dev->name, - idev, &idev->cnf); + int err; + + if (!sysctl_dev_name_is_allowed(idev->dev->name)) + return -EINVAL; + + err = neigh_sysctl_register(idev->dev, idev->nd_parms, + &ndisc_ifinfo_sysctl_change); + if (err) + return err; + err = __addrconf_sysctl_register(dev_net(idev->dev), idev->dev->name, + idev, &idev->cnf); + if (err) + neigh_sysctl_unregister(idev->nd_parms); + + return err; } static void addrconf_sysctl_unregister(struct inet6_dev *idev) @@ -5338,6 +5362,7 @@ static struct rtnl_af_ops inet6_ops = { int __init addrconf_init(void) { + struct inet6_dev *idev; int i, err; err = ipv6_addr_label_init(); @@ -5376,11 +5401,12 @@ int __init addrconf_init(void) * device and it being up should be removed. */ rtnl_lock(); - if (!ipv6_add_dev(init_net.loopback_dev)) - err = -ENOMEM; + idev = ipv6_add_dev(init_net.loopback_dev); rtnl_unlock(); - if (err) + if (IS_ERR(idev)) { + err = PTR_ERR(idev); goto errlo; + } for (i = 0; i < IN6_ADDR_HSIZE; i++) INIT_HLIST_HEAD(&inet6_addr_lst[i]); From 9c5ff24f963919965155cf0c4a2323b22a0c5c84 Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Fri, 25 Jul 2014 15:25:10 -0700 Subject: [PATCH 3/3] vlan: fail early when creating netdev named config Similarly, vlan will create /proc/net/vlan/, so when we create dev with name "config", it will confict with /proc/net/vlan/config. Reported-by: Stephane Chazelas Cc: "David S. Miller" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/8021q/vlan.c | 21 +++++++++++++-------- net/8021q/vlanproc.c | 2 ++ 2 files changed, 15 insertions(+), 8 deletions(-) diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index cba9c212a730..64c6bed4a3d3 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -325,23 +325,24 @@ static void vlan_transfer_features(struct net_device *dev, netdev_update_features(vlandev); } -static void __vlan_device_event(struct net_device *dev, unsigned long event) +static int __vlan_device_event(struct net_device *dev, unsigned long event) { + int err = 0; + switch (event) { case NETDEV_CHANGENAME: vlan_proc_rem_dev(dev); - if (vlan_proc_add_dev(dev) < 0) - pr_warn("failed to change proc name for %s\n", - dev->name); + err = vlan_proc_add_dev(dev); break; case NETDEV_REGISTER: - if (vlan_proc_add_dev(dev) < 0) - pr_warn("failed to add proc entry for %s\n", dev->name); + err = vlan_proc_add_dev(dev); break; case NETDEV_UNREGISTER: vlan_proc_rem_dev(dev); break; } + + return err; } static int vlan_device_event(struct notifier_block *unused, unsigned long event, @@ -356,8 +357,12 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event, bool last = false; LIST_HEAD(list); - if (is_vlan_dev(dev)) - __vlan_device_event(dev, event); + if (is_vlan_dev(dev)) { + int err = __vlan_device_event(dev, event); + + if (err) + return notifier_from_errno(err); + } if ((event == NETDEV_UP) && (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)) { diff --git a/net/8021q/vlanproc.c b/net/8021q/vlanproc.c index 1d0e89213a28..ae63cf72a953 100644 --- a/net/8021q/vlanproc.c +++ b/net/8021q/vlanproc.c @@ -171,6 +171,8 @@ int vlan_proc_add_dev(struct net_device *vlandev) struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev); struct vlan_net *vn = net_generic(dev_net(vlandev), vlan_net_id); + if (!strcmp(vlandev->name, name_conf)) + return -EINVAL; vlan->dent = proc_create_data(vlandev->name, S_IFREG|S_IRUSR|S_IWUSR, vn->proc_vlan_dir, &vlandev_fops, vlandev);