From e9e7e85d75f3731079ffd77c1a66f037aef04fe7 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 15 Jul 2019 12:00:20 +0200 Subject: xfrm interface: avoid corruption on changelink The new parameters must not be stored in the netdev_priv() before validation, it may corrupt the interface. Note also that if data is NULL, only a memset() is done. $ ip link add xfrm1 type xfrm dev lo if_id 1 $ ip link add xfrm2 type xfrm dev lo if_id 2 $ ip link set xfrm1 type xfrm dev lo if_id 2 RTNETLINK answers: File exists $ ip -d link list dev xfrm1 5: xfrm1@lo: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/none 00:00:00:00:00:00 brd 00:00:00:00:00:00 promiscuity 0 minmtu 68 maxmtu 1500 xfrm if_id 0x2 addrgenmode eui64 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 => "if_id 0x2" Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Signed-off-by: Nicolas Dichtel Tested-by: Julien Floret Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_interface.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'net/xfrm') diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index 74868f9d81fb..2310dc9e35c2 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -671,12 +671,12 @@ static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { - struct xfrm_if *xi = netdev_priv(dev); struct net *net = dev_net(dev); + struct xfrm_if_parms p; + struct xfrm_if *xi; - xfrmi_netlink_parms(data, &xi->p); - - xi = xfrmi_locate(net, &xi->p); + xfrmi_netlink_parms(data, &p); + xi = xfrmi_locate(net, &p); if (!xi) { xi = netdev_priv(dev); } else { @@ -684,7 +684,7 @@ static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[], return -EEXIST; } - return xfrmi_update(xi, &xi->p); + return xfrmi_update(xi, &p); } static size_t xfrmi_get_size(const struct net_device *dev) -- cgit v1.2.3 From e0aaa332e6a97dae57ad59cdb19e21f83c3d081c Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 15 Jul 2019 12:00:21 +0200 Subject: xfrm interface: ifname may be wrong in logs The ifname is copied when the interface is created, but is never updated later. In fact, this property is used only in one error message, where the netdevice pointer is available, thus let's use it. Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Signed-off-by: Nicolas Dichtel Signed-off-by: Steffen Klassert --- include/net/xfrm.h | 1 - net/xfrm/xfrm_interface.c | 10 +--------- 2 files changed, 1 insertion(+), 10 deletions(-) (limited to 'net/xfrm') diff --git a/include/net/xfrm.h b/include/net/xfrm.h index b22db30c3d88..ad761ef84797 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -983,7 +983,6 @@ static inline void xfrm_dst_destroy(struct xfrm_dst *xdst) void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev); struct xfrm_if_parms { - char name[IFNAMSIZ]; /* name of XFRM device */ int link; /* ifindex of underlying L2 interface */ u32 if_id; /* interface identifyer */ }; diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index 2310dc9e35c2..68336ee00d72 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -145,8 +145,6 @@ static int xfrmi_create(struct net_device *dev) if (err < 0) goto out; - strcpy(xi->p.name, dev->name); - dev_hold(dev); xfrmi_link(xfrmn, xi); @@ -294,7 +292,7 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) if (tdev == dev) { stats->collisions++; net_warn_ratelimited("%s: Local routing loop detected!\n", - xi->p.name); + dev->name); goto tx_err_dst_release; } @@ -638,12 +636,6 @@ static int xfrmi_newlink(struct net *src_net, struct net_device *dev, int err; xfrmi_netlink_parms(data, &p); - - if (!tb[IFLA_IFNAME]) - return -EINVAL; - - nla_strlcpy(p.name, tb[IFLA_IFNAME], IFNAMSIZ); - xi = xfrmi_locate(net, &p); if (xi) return -EEXIST; -- cgit v1.2.3 From c5d1030f23002430c2a336b2b629b9d6f72b3564 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 15 Jul 2019 12:00:22 +0200 Subject: xfrm interface: fix list corruption for x-netns dev_net(dev) is the netns of the device and xi->net is the link netns, where the device has been linked. changelink() must operate in the link netns to avoid a corruption of the xfrm lists. Note that xi->net and dev_net(xi->physdev) are always the same. Before the patch, the xfrmi lists may be corrupted and can later trigger a kernel panic. Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Reported-by: Julien Floret Signed-off-by: Nicolas Dichtel Tested-by: Julien Floret Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_interface.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net/xfrm') diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index 68336ee00d72..53e5e47b2c55 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -503,7 +503,7 @@ static int xfrmi_change(struct xfrm_if *xi, const struct xfrm_if_parms *p) static int xfrmi_update(struct xfrm_if *xi, struct xfrm_if_parms *p) { - struct net *net = dev_net(xi->dev); + struct net *net = xi->net; struct xfrmi_net *xfrmn = net_generic(net, xfrmi_net_id); int err; @@ -663,9 +663,9 @@ static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { - struct net *net = dev_net(dev); + struct xfrm_if *xi = netdev_priv(dev); + struct net *net = xi->net; struct xfrm_if_parms p; - struct xfrm_if *xi; xfrmi_netlink_parms(data, &p); xi = xfrmi_locate(net, &p); @@ -707,7 +707,7 @@ static struct net *xfrmi_get_link_net(const struct net_device *dev) { struct xfrm_if *xi = netdev_priv(dev); - return dev_net(xi->phydev); + return xi->net; } static const struct nla_policy xfrmi_policy[IFLA_XFRM_MAX + 1] = { -- cgit v1.2.3 From 22d6552f827ef76ade3edf6bbb3f05048a0a7d8b Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 15 Jul 2019 12:00:23 +0200 Subject: xfrm interface: fix management of phydev With the current implementation, phydev cannot be removed: $ ip link add dummy type dummy $ ip link add xfrm1 type xfrm dev dummy if_id 1 $ ip l d dummy kernel:[77938.465445] unregister_netdevice: waiting for dummy to become free. Usage count = 1 Manage it like in ip tunnels, ie just keep the ifindex. Not that the side effect, is that the phydev is now optional. Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Signed-off-by: Nicolas Dichtel Tested-by: Julien Floret Signed-off-by: Steffen Klassert --- include/net/xfrm.h | 1 - net/xfrm/xfrm_interface.c | 32 +++++++++++++++++--------------- 2 files changed, 17 insertions(+), 16 deletions(-) (limited to 'net/xfrm') diff --git a/include/net/xfrm.h b/include/net/xfrm.h index ad761ef84797..aa08a7a5f6ac 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -990,7 +990,6 @@ struct xfrm_if_parms { struct xfrm_if { struct xfrm_if __rcu *next; /* next interface in list */ struct net_device *dev; /* virtual device associated with interface */ - struct net_device *phydev; /* physical device */ struct net *net; /* netns for packet i/o */ struct xfrm_if_parms p; /* interface parms */ diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index 53e5e47b2c55..2ab4859df55a 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -175,7 +175,6 @@ static void xfrmi_dev_uninit(struct net_device *dev) struct xfrmi_net *xfrmn = net_generic(xi->net, xfrmi_net_id); xfrmi_unlink(xfrmn, xi); - dev_put(xi->phydev); dev_put(dev); } @@ -362,7 +361,7 @@ static netdev_tx_t xfrmi_xmit(struct sk_buff *skb, struct net_device *dev) goto tx_err; } - fl.flowi_oif = xi->phydev->ifindex; + fl.flowi_oif = xi->p.link; ret = xfrmi_xmit2(skb, dev, &fl); if (ret < 0) @@ -548,7 +547,7 @@ static int xfrmi_get_iflink(const struct net_device *dev) { struct xfrm_if *xi = netdev_priv(dev); - return xi->phydev->ifindex; + return xi->p.link; } @@ -574,12 +573,14 @@ static void xfrmi_dev_setup(struct net_device *dev) dev->needs_free_netdev = true; dev->priv_destructor = xfrmi_dev_free; netif_keep_dst(dev); + + eth_broadcast_addr(dev->broadcast); } static int xfrmi_dev_init(struct net_device *dev) { struct xfrm_if *xi = netdev_priv(dev); - struct net_device *phydev = xi->phydev; + struct net_device *phydev = __dev_get_by_index(xi->net, xi->p.link); int err; dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); @@ -594,13 +595,19 @@ static int xfrmi_dev_init(struct net_device *dev) dev->features |= NETIF_F_LLTX; - dev->needed_headroom = phydev->needed_headroom; - dev->needed_tailroom = phydev->needed_tailroom; + if (phydev) { + dev->needed_headroom = phydev->needed_headroom; + dev->needed_tailroom = phydev->needed_tailroom; - if (is_zero_ether_addr(dev->dev_addr)) - eth_hw_addr_inherit(dev, phydev); - if (is_zero_ether_addr(dev->broadcast)) - memcpy(dev->broadcast, phydev->broadcast, dev->addr_len); + if (is_zero_ether_addr(dev->dev_addr)) + eth_hw_addr_inherit(dev, phydev); + if (is_zero_ether_addr(dev->broadcast)) + memcpy(dev->broadcast, phydev->broadcast, + dev->addr_len); + } else { + eth_hw_addr_random(dev); + eth_broadcast_addr(dev->broadcast); + } return 0; } @@ -644,13 +651,8 @@ static int xfrmi_newlink(struct net *src_net, struct net_device *dev, xi->p = p; xi->net = net; xi->dev = dev; - xi->phydev = dev_get_by_index(net, p.link); - if (!xi->phydev) - return -ENODEV; err = xfrmi_create(dev); - if (err < 0) - dev_put(xi->phydev); return err; } -- cgit v1.2.3 From 769a807d0b41df4201dbeb01c22eaeb3e5905532 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 12 Aug 2019 10:32:13 +0200 Subject: xfrm: policy: avoid warning splat when merging nodes syzbot reported a splat: xfrm_policy_inexact_list_reinsert+0x625/0x6e0 net/xfrm/xfrm_policy.c:877 CPU: 1 PID: 6756 Comm: syz-executor.1 Not tainted 5.3.0-rc2+ #57 Call Trace: xfrm_policy_inexact_node_reinsert net/xfrm/xfrm_policy.c:922 [inline] xfrm_policy_inexact_node_merge net/xfrm/xfrm_policy.c:958 [inline] xfrm_policy_inexact_insert_node+0x537/0xb50 net/xfrm/xfrm_policy.c:1023 xfrm_policy_inexact_alloc_chain+0x62b/0xbd0 net/xfrm/xfrm_policy.c:1139 xfrm_policy_inexact_insert+0xe8/0x1540 net/xfrm/xfrm_policy.c:1182 xfrm_policy_insert+0xdf/0xce0 net/xfrm/xfrm_policy.c:1574 xfrm_add_policy+0x4cf/0x9b0 net/xfrm/xfrm_user.c:1670 xfrm_user_rcv_msg+0x46b/0x720 net/xfrm/xfrm_user.c:2676 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2477 xfrm_netlink_rcv+0x74/0x90 net/xfrm/xfrm_user.c:2684 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x809/0x9a0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0xa70/0xd30 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg net/socket.c:657 [inline] There is no reproducer, however, the warning can be reproduced by adding rules with ever smaller prefixes. The sanity check ("does the policy match the node") uses the prefix value of the node before its updated to the smaller value. To fix this, update the prefix earlier. The bug has no impact on tree correctness, this is only to prevent a false warning. Reported-by: syzbot+8cc27ace5f6972910b31@syzkaller.appspotmail.com Signed-off-by: Florian Westphal Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_policy.c | 6 ++++-- tools/testing/selftests/net/xfrm_policy.sh | 7 +++++++ 2 files changed, 11 insertions(+), 2 deletions(-) (limited to 'net/xfrm') diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 8ca637a72697..0fa7c5ce3b2c 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -912,6 +912,7 @@ restart: } else if (delta > 0) { p = &parent->rb_right; } else { + bool same_prefixlen = node->prefixlen == n->prefixlen; struct xfrm_policy *tmp; hlist_for_each_entry(tmp, &n->hhead, bydst) { @@ -919,9 +920,11 @@ restart: hlist_del_rcu(&tmp->bydst); } + node->prefixlen = prefixlen; + xfrm_policy_inexact_list_reinsert(net, node, family); - if (node->prefixlen == n->prefixlen) { + if (same_prefixlen) { kfree_rcu(n, rcu); return; } @@ -929,7 +932,6 @@ restart: rb_erase(*p, new); kfree_rcu(n, rcu); n = node; - n->prefixlen = prefixlen; goto restart; } } diff --git a/tools/testing/selftests/net/xfrm_policy.sh b/tools/testing/selftests/net/xfrm_policy.sh index 5445943bf07f..7a1bf94c5bd3 100755 --- a/tools/testing/selftests/net/xfrm_policy.sh +++ b/tools/testing/selftests/net/xfrm_policy.sh @@ -106,6 +106,13 @@ do_overlap() # # 10.0.0.0/24 and 10.0.1.0/24 nodes have been merged as 10.0.0.0/23. ip -net $ns xfrm policy add src 10.1.0.0/24 dst 10.0.0.0/23 dir fwd priority 200 action block + + # similar to above: add policies (with partially random address), with shrinking prefixes. + for p in 29 28 27;do + for k in $(seq 1 32); do + ip -net $ns xfrm policy add src 10.253.1.$((RANDOM%255))/$p dst 10.254.1.$((RANDOM%255))/$p dir fwd priority $((200+k)) action block 2>/dev/null + done + done } do_esp_policy_get_check() { -- cgit v1.2.3