From 173756b86803655d70af7732079b3aa935e6ab68 Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Fri, 13 Mar 2020 06:50:14 +0000 Subject: [PATCH 1/3] hsr: use rcu_read_lock() in hsr_get_node_{list/status}() hsr_get_node_{list/status}() are not under rtnl_lock() because they are callback functions of generic netlink. But they use __dev_get_by_index() without rtnl_lock(). So, it would use unsafe data. In order to fix it, rcu_read_lock() and dev_get_by_index_rcu() are used instead of __dev_get_by_index(). Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller --- net/hsr/hsr_framereg.c | 9 ++------- net/hsr/hsr_netlink.c | 39 +++++++++++++++++++++------------------ 2 files changed, 23 insertions(+), 25 deletions(-) diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c index 3ba7f61be107..a64bb64935a6 100644 --- a/net/hsr/hsr_framereg.c +++ b/net/hsr/hsr_framereg.c @@ -482,12 +482,9 @@ int hsr_get_node_data(struct hsr_priv *hsr, struct hsr_port *port; unsigned long tdiff; - rcu_read_lock(); node = find_node_by_addr_A(&hsr->node_db, addr); - if (!node) { - rcu_read_unlock(); - return -ENOENT; /* No such entry */ - } + if (!node) + return -ENOENT; ether_addr_copy(addr_b, node->macaddress_B); @@ -522,7 +519,5 @@ int hsr_get_node_data(struct hsr_priv *hsr, *addr_b_ifindex = -1; } - rcu_read_unlock(); - return 0; } diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c index 8dc0547f01d0..d6760df2ad1f 100644 --- a/net/hsr/hsr_netlink.c +++ b/net/hsr/hsr_netlink.c @@ -251,15 +251,16 @@ static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info) if (!na) goto invalid; - hsr_dev = __dev_get_by_index(genl_info_net(info), - nla_get_u32(info->attrs[HSR_A_IFINDEX])); + rcu_read_lock(); + hsr_dev = dev_get_by_index_rcu(genl_info_net(info), + nla_get_u32(info->attrs[HSR_A_IFINDEX])); if (!hsr_dev) - goto invalid; + goto rcu_unlock; if (!is_hsr_master(hsr_dev)) - goto invalid; + goto rcu_unlock; /* Send reply */ - skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); + skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); if (!skb_out) { res = -ENOMEM; goto fail; @@ -313,12 +314,10 @@ static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info) res = nla_put_u16(skb_out, HSR_A_IF1_SEQ, hsr_node_if1_seq); if (res < 0) goto nla_put_failure; - rcu_read_lock(); port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A); if (port) res = nla_put_u32(skb_out, HSR_A_IF1_IFINDEX, port->dev->ifindex); - rcu_read_unlock(); if (res < 0) goto nla_put_failure; @@ -328,20 +327,22 @@ static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info) res = nla_put_u16(skb_out, HSR_A_IF2_SEQ, hsr_node_if2_seq); if (res < 0) goto nla_put_failure; - rcu_read_lock(); port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B); if (port) res = nla_put_u32(skb_out, HSR_A_IF2_IFINDEX, port->dev->ifindex); - rcu_read_unlock(); if (res < 0) goto nla_put_failure; + rcu_read_unlock(); + genlmsg_end(skb_out, msg_head); genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid); return 0; +rcu_unlock: + rcu_read_unlock(); invalid: netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL); return 0; @@ -351,6 +352,7 @@ static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info) /* Fall through */ fail: + rcu_read_unlock(); return res; } @@ -377,15 +379,16 @@ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info) if (!na) goto invalid; - hsr_dev = __dev_get_by_index(genl_info_net(info), - nla_get_u32(info->attrs[HSR_A_IFINDEX])); + rcu_read_lock(); + hsr_dev = dev_get_by_index_rcu(genl_info_net(info), + nla_get_u32(info->attrs[HSR_A_IFINDEX])); if (!hsr_dev) - goto invalid; + goto rcu_unlock; if (!is_hsr_master(hsr_dev)) - goto invalid; + goto rcu_unlock; /* Send reply */ - skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); + skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); if (!skb_out) { res = -ENOMEM; goto fail; @@ -405,14 +408,11 @@ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info) hsr = netdev_priv(hsr_dev); - rcu_read_lock(); pos = hsr_get_next_node(hsr, NULL, addr); while (pos) { res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN, addr); - if (res < 0) { - rcu_read_unlock(); + if (res < 0) goto nla_put_failure; - } pos = hsr_get_next_node(hsr, pos, addr); } rcu_read_unlock(); @@ -422,6 +422,8 @@ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info) return 0; +rcu_unlock: + rcu_read_unlock(); invalid: netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL); return 0; @@ -431,6 +433,7 @@ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info) /* Fall through */ fail: + rcu_read_unlock(); return res; } From ca19c70f5225771c05bcdcb832b4eb84d7271c5e Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Fri, 13 Mar 2020 06:50:24 +0000 Subject: [PATCH 2/3] hsr: add restart routine into hsr_get_node_list() The hsr_get_node_list() is to send node addresses to the userspace. If there are so many nodes, it could fail because of buffer size. In order to avoid this failure, the restart routine is added. Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller --- net/hsr/hsr_netlink.c | 42 ++++++++++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 16 deletions(-) diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c index d6760df2ad1f..726bfe923999 100644 --- a/net/hsr/hsr_netlink.c +++ b/net/hsr/hsr_netlink.c @@ -360,16 +360,14 @@ static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info) */ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info) { - /* For receiving */ - struct nlattr *na; - struct net_device *hsr_dev; - - /* For sending */ - struct sk_buff *skb_out; - void *msg_head; - struct hsr_priv *hsr; - void *pos; unsigned char addr[ETH_ALEN]; + struct net_device *hsr_dev; + struct sk_buff *skb_out; + struct hsr_priv *hsr; + bool restart = false; + struct nlattr *na; + void *pos = NULL; + void *msg_head; int res; if (!info) @@ -387,8 +385,9 @@ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info) if (!is_hsr_master(hsr_dev)) goto rcu_unlock; +restart: /* Send reply */ - skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); + skb_out = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_ATOMIC); if (!skb_out) { res = -ENOMEM; goto fail; @@ -402,17 +401,28 @@ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info) goto nla_put_failure; } - res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex); - if (res < 0) - goto nla_put_failure; + if (!restart) { + res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex); + if (res < 0) + goto nla_put_failure; + } hsr = netdev_priv(hsr_dev); - pos = hsr_get_next_node(hsr, NULL, addr); + if (!pos) + pos = hsr_get_next_node(hsr, NULL, addr); while (pos) { res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN, addr); - if (res < 0) + if (res < 0) { + if (res == -EMSGSIZE) { + genlmsg_end(skb_out, msg_head); + genlmsg_unicast(genl_info_net(info), skb_out, + info->snd_portid); + restart = true; + goto restart; + } goto nla_put_failure; + } pos = hsr_get_next_node(hsr, pos, addr); } rcu_read_unlock(); @@ -429,7 +439,7 @@ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info) return 0; nla_put_failure: - kfree_skb(skb_out); + nlmsg_free(skb_out); /* Fall through */ fail: From 09e91dbea0aa32be02d8877bd50490813de56b9a Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Fri, 13 Mar 2020 06:50:33 +0000 Subject: [PATCH 3/3] hsr: set .netnsok flag The hsr module has been supporting the list and status command. (HSR_C_GET_NODE_LIST and HSR_C_GET_NODE_STATUS) These commands send node information to the user-space via generic netlink. But, in the non-init_net namespace, these commands are not allowed because .netnsok flag is false. So, there is no way to get node information in the non-init_net namespace. Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller --- net/hsr/hsr_netlink.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c index 726bfe923999..fae21c863b1f 100644 --- a/net/hsr/hsr_netlink.c +++ b/net/hsr/hsr_netlink.c @@ -470,6 +470,7 @@ static struct genl_family hsr_genl_family __ro_after_init = { .version = 1, .maxattr = HSR_A_MAX, .policy = hsr_genl_policy, + .netnsok = true, .module = THIS_MODULE, .ops = hsr_ops, .n_ops = ARRAY_SIZE(hsr_ops),